More and Less Exciting Things

Universal patterns in language and behavior reveal that pairs of psychological opposites are structured such that one component is more arousing than the other.

What, was he sad, or merry?
Like to the time o’ the year between the extremes
Of hot and cold, he was nor sad nor merry.

— Shakespeare, Antony and Cleopatra (2022)

Perceptual heat, fluidity, motion, speed, disorder, brightness, the so-called “warmer” colors red, orange and yellow, sound, loudness, high pitch, upwardness, outwardness, the left side, spikiness, length, large size, large numbers of things and novelty tend to be more exciting to animals than their opposites: coldness, solidness, stasis, slowness, order, darkness, the “cooler” colors purple, blue and green, silence, quietness, low pitch, downwardness, inwardness, the right side, roundness, small size, small numbers of things and familiarity.

These qualities, listed below, are examples of a large set of opposites that we appear to distinguish, understand and appreciate by way of differential excitement (arousal), possibly through subtle differences in how they influence brain temperature, sometimes directly so in the case of heat and cold, otherwise indirectly by way of sensory signals and the level of neurological excitation they convey.

More exciting things (list 1): heat, fluidity, dynamism, speed, disorder, brightness, warm colors, sound, loudness, high pitch, upwardness, outwardness, the left side, length, spikiness, large size, multiplicity, novelty.

Less exciting things (list 2): coldness, solidness, stasis, slowness, order, darkness, cool colors, silence, quietness, low pitch, downwardness, inwardness, the right side, shortness, roundness, small size, small numbers, familiarity.

The qualities in list 1 and their conceptual relatives are used figuratively to describe higher states of arousal like anger, passion, happiness, humor, intoxication and insanity, and often to mean excitement itself, in addition to their literal meanings. They stand for impropriety, disobedience, disagreement, informality, generality, effortlessness (easiness), fantasy, uncertainty, dominance, danger, evil and lies, and they’re used euphemistically to counter the unexcitingness of death, loss and other unpleasant events, more so at least than the qualities in list 2 and their conceptual relatives, which tend to denote less excitement and lower arousal states like sadness, boredom, seriousness, sobriety and sanity. List 2 qualities describe rules, laws, difficulty (hardness), reality, certainty, knowledge, agreement, formality, specificity, submission, safety, goodness and the truth, and they counter the unpleasantness of overly exciting behavior and situations.

Thus, pairs of more recently derived conceptual opposites are organized in the mind according to the same system of differential excitement that animals have been using for millions of years to understand each other and their surroundings. They function something like an operating system of the mind, with higher level concepts relying on them to “make sense.”

List 1 and 2 qualities involve extremely primitive sensory abilities, those we use to comprehend temperature, texture, motion, light, color, sound, shape and direction. They can be experienced by all animals with appropriate sensory systems. Mammals, birds, reptiles, fish, arthropods, mollusks and others, even our most distant animal relatives, probably think of them as opposites just as we do. It’s not hard to imagine these abilities having side effects in the form of biases that persist despite being adaptively neutral, or even detrimental but negligibly so compared to the benefits of seeing and hearing, knowing the difference between wet and dry, between motion and stasis, night and day, sound and silence, long and round, up and down, out and in and so on.

There are, of course, more and less exciting things to be considered apart from those listed above. Some of them also represent primitive perceptual opposites (e.g., forward versus backward, front versus back, peripheral versus central, expansion versus contraction, freedom versus confinement), while others are more recently derived (e.g., evil versus good, soul versus body, win versus lose). Some of these are addressed in Other Mixtures, and discussed to some extent throughout the text, but they’re only a fraction of the opposites we seem to understand by way of differential excitement.

For almost every pair of opposites that we recognize universally, it’s easy to determine that one component is more exciting than the other. In fact, it’s difficult to identify psychological dualities to which this doesn’t apply. Differential excitement across so many perceptual dimensions and aspects of consciousness probably means it has something to do with the way sensory systems work. The phenomenon is so common it’s reasonable to conclude it occurs inevitably, that we wouldn’t be able to tell the difference between opposites without it.

Linguistic Patterns

I can resist everything except temptation.

— Oscar Wilde, Lady Windermere’s Fan, A Play About a Good Woman

Linguistic patterns demonstrate differential excitement between list 1 and list 2 qualities. For example, we call undesirably ordinary or unexciting things “cold,” “icy” (cold/solid), “dry” (solid), “stale” (solid), “stiff” (solid), “tired” (stasis), “slow,” “lifeless” (static), “tame,” “square” (order), “flat” (order), “lackluster” (dark), “drab,” “ho-hum” (low pitch), “meh” (low pitch), “monotonous” (orderly sound) “underwhelming” (down), “boring” (inward), “dull” (not spiky/round), “small” and “ordinary” (order/familiar), despite the lack of a consistent, outwardly observable reason to do so, and as if they fail to satisfy a desire for some amount of heat, fluidity, dynamism, disorder, brightness, high pitch, variation, spikiness, large size and outwardness, which represent higher excitement in “things are heating up,” “a fever pitch” (heat), “on cloud nine” (fluid/multiple), “boiling over” (hot/fluid/up), “blood boiling” (red/fluid/hot), “make a splash,” “get a rush” (speed), “earth shaking” (dynamic), “earth shattering” (disorder), “cracked up” (disorder/up), “all hell broke loose” (many/hot/disorder/free), “bright and breezy” (bright/fluid), “tickled pink” (bright), “rosy” (red), “red hot” (bright/red), “buzzing” (high pitch), “alarmed” (loud/high pitch), “riled up,” “shook up” (dynamic/up), “sensory overload” (over/up), “freaking out,” “blown away” (away/outward), “on pins and needles” (spiky), “a big deal” (large size) and “no small matter.”

Similar patterns in language demonstrate the other connections suggested, which can be stated metaphorically, as in: anger and passion are hot, uncertainty and humor are fluid-like, insanity is outward and disorderly, certainty is solid and orderly, happiness is upward and bright, sadness is downward and dark, dominance is higher, submission is lower, difficulty is hard, lies are smoke and so on. Hundreds of linguistic examples of these connections are listed in the following section:Differential Excitement in Language. Such expressions evolve and persist in the structure of languages because they’re congruent with unconscious associations. They feel like the right references to be used in the contexts we use them by satisfying our preexisting expectations, although we apply them unconsciously.

Differential Excitement in Language

The following lists give examples of common expressions that connect list 1 and 2 qualities to more or less excitement, as proposed above, to higher and lower arousal emotions (e.g., anger, sexuality, happiness, intoxication, insanity, depression, sadness, boredom, sobriety and sanity), and to the concepts of truth, lies, fantasy, reality, humor, seriousness and so on.

Expressions that demonstrate mental categories are included. For example “lower your voice,” “quiet down” and “keep it down” connect the list 2 qualities of quietness and downwardness (quiet=down). The lists are laid out so that qualities from list 1 alternate with their opposites from list 2. Some of the expressions are followed by short descriptions of their meanings in parentheses, especially if the meaning isn’t well known.

Heat and Coldness

Heat (34): a flame (romantic relationship), a hot date, a hotbed, a hotspot, a short fuse (excitable), a smoke show (sexuality), add fuel to the fire (more/fluid/hot), all fired up, ball of fire (energetic), barnburner (exciting), blow a fuse (anger), breathing fire (angry=fluid/hot), burning desire (heat=sexuality), burning with rage (heat=anger), fan the flames, fired up (excited), five-alarm fire, furious (heat=anger), he/she is hot (sexuality), heated argument, hothead (excitable), hot damn, hot diggity dog, hot-tempered (anger), in heat (sexuality), in hot water, in the hot seat, inflame the situation (excitement), inflammatory, playing with fire, spitting fire (angry=fluid/hot/out), temper tantrum, the heat of passion (sexuality), things are heating up, torrid romance, steam coming out of the ears (fluid/out~in), emit smoke from seven orifices (fluid/many/out, Chinese idiom).

Cold (22): a cool head (calmness), chill, chill out, chillin, cool calm and collected, cold comfort, cool as a cucumber (calmness), cool down (calmness), play it cool, cool your heels (calm down), cool your jets (calm down), lower the temperature (calm down), out cold (unconscious), cold shoulder (indifference), cold as ice (unemotional), cold fish (unemotional), in the cold light of day (reality).

Fluidity and Solidness

Fluidity (64): add fuel to the fire, all gas and gaiters (nonsense), bad blood (disagreement), before the wind (fast), blood was boiling (anger), blow air with the bellows (a Spanish idiom for sex), blow it out of the water, blow off steam, blow smoke (lie), blow the lid off, blow your top (anger), blown out of proportion, boil over (intense emotions), breeze away (speed), cause a stir (cause excitement), cooking with gas (speed), cream of the crop, don't make waves, drooling over, fan the flames, foaming at the mouth, full of piss and vinegar (energetic), fuming (angry), gaining steam (more/fluid), gaslighting (dishonesty), get a second wind (energy), gushing, have a gas, have a meltdown, have the wind up (be anxious), huffing and puffing (upset), in full flow (fast), juicy, lickety split (fast), mad as a wet hen (anger), make a splash (exciting), on cloud nine, open the floodgates, out for blood (anger), outpouring, pleased as punch, simmer down, sleazy (sexuality), slick as a whistle (high pitch), smoke-show (sexuality), souped-up, sow the wind and reap the whirlwind, spitting fire (very angry), spitting mad (very angry), steam your beam (very angry), steamy (sexuality), stewing (angry), stir things up a little, stir up trouble, take my breath away, take the wind out of your sails, the calm before the storm, trouble is brewing, turbulent times, waiting with bated breath, walking on air (ecstatic), weak sauce, where there's smoke there's fire, windmills in your head (crazy).

Solidness/Dryness (18): bone idle (stasis), carved in stone (certain), crystal clear (certain), feel it in my bones (certain), hard times (difficulty), hard-pressed (difficulty), home and dry (ending), like watching paint dry (boring), bored stiff, rock bottom, solid argument (reality), solid as a rock (stability), hard as nails (unsentimental), hard-nosed (realistic), the hard way (difficult), dry as dust (boring), es un peñazo: “it is a big rock” meaning boring in Spanish, 따분하다: “stale” meaning extremely boring in Korean.

Dynamism, Speed, Stasis and Slowness

Dynamism and speed (20): a fast temper (anger), a quick temper (anger), actions speak louder than words (dynamism=loudness), all shook up (many/dynamic/up), drive me crazy (dynamism/disorder), drive me wild (dynamism/disorder), emotional (motion), flip out (dynamic/out), get a rush (excited), get some action (sexuality), go crazy (dynamic/disorder), go for broke (dynamic/disorder), go hog wild (dynamic/disorder), go mad, go nuts, raring to go, life in the fast lane (exciting life), riding high, running amok, running roughshod.

Stasis and slowness (10): bored to death (unexciting), dead on (correct), dead set (certain=stasis), no great shakes, slow (boring), slow your roll (calm down), slow on the uptake (unintelligent), a bit slow (unintelligent), unmoved (unexcited), snooze fest (boring).

Disorder and Order

Disorder (47): a firecracker, a crook (impropriety), a smash hit, banging, bend the truth (falsehood=disorder), break into song (sound=disorder), break the rules (impropriety=disorder), bursting at the seams, bust a nut (sexuality), bust up, by cracky (surprise), crack a smile (happiness=disorder), crack the whip, crackhead (intoxication), crackpot (insanity), deranged (insanity), dirty language (impropriety=disorder) dirty rat (offensive), dirty trick (dishonesty), don’t twist my arm (annoyance), get all bent out of shape, get bent (offensive), get cracking (energy), get dirty (sexuality), get freaky (sexuality), get kinky (sexuality), get nasty (sexuality), having a blast, in your wildest dreams, just for a twist (novelty=disorder), let it rip (dynamism=disorder), like gangbusters (energetic), loose cannon, make a crack, nervous breakdown, not all it’s cracked up to be (not that exciting), on a tear (speed=disorder), play dirty (dishonesty), read the riot act, rough you up, shaken up, storming mad, twist the truth (lies), twisted, wisecrack, with a twist (novelty=disorder), wrongheaded (falsehood=disorder), you’re cracking me up (humor).

Order (11) a clear conscience (goodness), come clean (truth), conscience is clean (goodness), even-keeled, get square (fairness), level-headed (calm), on the level (honest), on the square (honest), shape up (goodness=order), straighten up, with clear eyes (reality).

Brightness, Darkness, Warm and Cool Colors

Brightness and warm colors (16): a heavy purse makes a light heart, all moonlight and roses (positive), all sweetness and light, bedazzled, bright and breezy, bright-eyed and bushy-tailed (bright/spiky), dazzled, eyes light up, in its heyday, it dawned on me (bright=novel), light at the end of the tunnel (positive), light up the room, light-hearted, lighten the mood, like a red flag to a bull (anger), newsflash, tickled pink (excited), red hot (exciting), see through rose-tinted glasses (optimism).

Darkness and cool colors (6): baby blues, dark times, dark days, darken the mood, feel blue (sad), have the blues (sad), dead of night (darkness=stasis), broyer du noir: “crush some dark” in French meaning to feel very depressed, verlo todo negro: “see everything dark” in Spanish meaning pessimistic and negative.

Sound, Loudness, High Pitch, Silence, Quietness and Low Pitch

Sound, loudness and high pitch (14): alarmed, alarming, all cry and no wool (many/loud/high-pitched), all horns and rattles (spiky/loud/high-pitched), barking mad (crazy), buzzing, mad as a hornet, no screaming hell (not exciting), on the fiddle (dishonest), rattled, uproar (up/loud=excitement), whistling Dixie (optimistic), whistling in the dark (optimistic), whistling past the graveyard (optimistic), with bells on.

Silence, quietness and low pitch (6): ho-hum, nothing to shout about, peace and quiet (calm), lower your voice (quiet=downward), quiet down (quiet=downward), keep it down (quiet=downward), a deep voice (low pitch=downward/inward).

Up and Down

Up (50): a bang-up time (fun), a blowup, a toss up (uncertain), above and beyond, all riled up, all shook up (many/dynamic/up), all worked up, all wound up, amped-up, blow your top, crank it up (intensify), fed up, flight of fancy (unrealistic), floating on air (happy), fly off the handle, flying high, get off your high horse (superiority), get your hopes up, go through the roof, high alert, high spirits, high stakes (up/spiky), high strung, hopping mad, I’ve had it up to here, jumping for joy (happiness), on the upside, on top of the world, over done, over the moon (happy), over the top (up/up), overall (generality), overhyped, overwhelming, overzealous, raise the stakes, raising a ruckus, raising hell, raising red flags (up/bright/fluid), riding high, sensory overload (too exciting), super! (excited), suspense (up=uncertain), up in arms, up to no good, upheaval, uplifting (happy), upset (angry), exalted (superiority), escalate.

Down (32): a Debbie downer (sad), a downer (sad), below par, bring down a peg or two, calm down, dampen down, dial it down (lower the intensity), diddly squat (down=none), down and out, down in the doldrums (sad), down in the dumps (sad), down in the mouth (sad), down on your luck, down trodden, down with (agreement), downplay, drop by (downward=entry), drop in (downward=entry), feeling down, feeling low, hit rock bottom (solid/down), let down (disappointment), low spirits (down~fluid), on the downside, settle down, simmer down, something got you down?, subdued, under the weather, understatement, underwhelming, deescalate.

Out and In

Out (13): a bad trip (intense), all shot to hell, away with the fairies (crazy), bliss out, blown away (overwhelmed), blown out of proportion (fluid/out/big), extrovert, far and away, flipping out (dynamic/out), freaking out, jump out of your skin, go all out (dynamic/many/out), out for blood (out/fluid/red=angry), out of it, rip off (disorder/out=dishonest).

In (18): it’s a pity (sad=down/in), bottom of the barrel (down/in=unexciting), come to grips (understand), down in a hole (down/in/in), heart in my boots, in a funk, in the doldrums, in a dark place, from the bottom of my heart (down/in=honest), introvert, keep it down (quiet), pull it back, pull it together, reel it in, shortcomings, stuck in a rut, take it easy (in=calm down), with a heavy heart.

Spikiness, Length and Roundness

Spikiness (8): a barb, a sharp tongue, bristle with rage (angry), my hair stood on end, on pins and needles (excited), prick (insult), prickly, razor sharp (witty), sharp (smart).

Length (5): a long shot (unlikely), an arm and a leg (many), go to any length, go to great lengths, my patience is wearing thin (thin=angry), widespread (general), with a broad brush (general).

Roundness/Dullness (7): cold as balls (coldness=roundness), see eye to eye (agreement), in point of fact (round=real), on point (correct), dull (boring), dull as dishwater (boring).

Large and Small Size

Large size (11): a big deal (exciting), a whale of a time, a huge deal (exciting), at large (outward), big into, big on, big up, bold, larger than life (dynamism), no small matter (exciting), the big cheese (dominance).

Small size (10): don’t sweat the small stuff, feel small, lay low and sing small, small fry, small time, small talk, small wonder (unsuprising), small potatoes, take it with a grain of salt (in/single/small/solid), the worlds smallest violin.

Multiplicity

More (18): all the rage, at sixes and sevens (craziness), double or nothing, double trouble, double-tongued (deceitful), excessive, extraordinary, feel like a million bucks (happy), from zero to sixty, hit for six (upset), hope springs eternal, in full flow (fast), in full swing (fast), in seventh heaven (happy), like a dog with two tails (very excited), on the double (fast), two-faced (deceitful), utmost.

Less (10): a nothing burger, an empty shell, bar none (certain), emptiness, glass half empty, feel nothing inside, inner void, nothing special, nothing to write home about, too little too late.

Gestures

Human gestures of high excitement are apparently more likely to include list 1 qualities, and the opposite is generally true for gestures of low excitement. The fact that the gestures listed below are structured like language in this respect makes sense if one assumes both types of communication evolved to exploit preexisting biases of differential excitement between the qualities in lists 1 and 2, and it argues against the experiential thesis of conceptual metaphor, while supporting that of associations between the qualities in each list, or primitive mental categories.

Higher excitement gestures: spitting (fluid/out), faster movement, pacing, spinning, hand flapping, yelling, screaming (loud/high pitch/disorder), crying, singing, clapping, jumping, arm raising, thumbs up, high-fives, upwardness and outwardness of the body and body parts (head, arms, fingers).

Lower excitement gestures: slower movement, silence, quietness, thumbs down, downwardness and inwardness of the body and body parts (limbs, head, fingers).

Given the primitive nature of the sensory systems underlying animal abilities to detect the qualities in question, it wouldn’t be surprising to find that animals of all kinds have evolved or learned to reference them in a similar, dualistic manner with respect to arousal.

Across taxa swinging limbs, jumping and bouncing, rapid upward tail wagging, fast wing movements, expansion of the body, hair or feathers to increase spikiness and size, and loud, higher-pitched, rapid vocalizations are ways that animals relay higher excitement. Implicitly, the opposite actions are indicative of lower arousal. This outcome is extremely improbable in the absence of a set of universal psychological traits in the receivers of these signals that the signals have evolved to exploit. For example, both birds and mammals automatically interpret dynamic, upward and outward behavior as indicators of excitement because these qualities have always produced more arousal in observers than their opposites, going back at least to the common ancestors of these groups.

It might seem obvious that sensory systems would work such that a quality like motion draws attention and puts us in an alerted state, so that we can be ready to react and protect ourselves. However, not every quality in list 1 is necessarily a sign of danger (redness, disorder, length), and arousing gestures are employed in a wide variety of contexts. They also occur frequently in courtship rituals, where they’re meant to amuse and attract members of the opposite sex, although in these cases they tend to be juxtaposed in intricate patterns with less exciting gestures and sounds.

Notes

Perplexity’s response to “Compare the features of high arousal gestures versus low arousal gestures.”

High arousal gestures are larger, faster, and more expansive, while low arousal gestures are smaller, slower, and more contained.

High arousal: Movements are large in amplitude, fast, and often jerky or high-velocity, with arms raised, extended, or repeatedly opening and closing. Low arousal: Movements are reduced in amplitude, slower, smoother, and may show general motor slowing or minimal gesturing.

Posture and spatial extension

High arousal: Postures are expanded and space-occupying, with the chest open, shoulders lifted, arms stretched out in front or to the sides, and an “open” stance. Low arousal: Postures are contracted or withdrawn, with slumped shoulders, inward rotation, head down, and a smaller overall body silhouette.

Action readiness and direction

High arousal: Gestures often exhibit clear action tendencies (e.g., punching, emphatic pointing, forceful illustrators) and may be directed outward into extrapersonal space, signaling readiness to act or engage. Low arousal: Gestures may be more self-focused (self-touch, self-adaptors) or show withdrawal, signaling reduced readiness to act and a tendency to conserve energy or disengage.

Rhythm, variability, and organization

High arousal: Gesture sequences are more frequent and dynamically varied, with rapid preparation–stroke–retraction cycles and higher overall movement activity. Low arousal: Gestures are infrequent, sometimes stereotyped, with longer pauses, less rhythmic variation, and extended rest phases.

Attention

List 1 qualities are used in human culture to get attention, as warnings for instance, and by other animals both as warnings to potential predators and as sexual signals that attract mates and indicate fertility, although sexually selected features are typically elaborate, incorporating list 2 qualities as well.

Arousal is closely linked to attention, in that we tend to notice and focus on stimuli that excite us, known as “physically salient stimuli,” including bright, red, yellow, saturated, sharp, moving and rapidly growing objects, loud, high-pitched and irregular sounds, and novelty, as well as more specific phenomena like angry faces, blood, erotica, profanity and scenes or situations that violate our expectations.

For some salient stimuli it’s easy to think of how we would benefit from giving them extra attention. It seems like an obvious advantage to notice an angry face in a group of individuals who are otherwise content, because there’s a greater chance that person might do us harm. Likewise, a sharp object might be noticed at the expense of a round object because it’s more of a threat. From an evolutionary perspective, of course, this would require that our ancestors were killed by angry-looking individuals and sharp objects at a higher rate than they were killed by non-angry individuals and round objects, which sounds entirely likely, although it doesn’t necessarily address why a person would benefit from looking angry or why a particular facial configuration should come off as such to an observer.

It’s not so easy to imagine why red should be more salient than blue, high pitch more so than low pitch, irregularity more so than regularity, or the left side more so than the right. The lack of an obvious, immediate adaptive purpose for differential excitement in these and other perceptual dimensions supports the idea that arousal is essential to the process of distinguishing between opposites, and that it evolves to be part of sensory systems regardless of whether it plays a direct role in survival.

Assuming the attention-grabbing tendency of red, orange and yellow is an inherent, unavoidable feature of color vision can explain the evolution of these colors as advertisements in flowers, fruits, sexual organs and courtship coloration patterns. This perspective is parsimonious because it avoids the need for countless independent explanations of a predilection for these colors in pollinators, frugivores and mates.

For instance, a random mutation in a plant that causes bright and warmly-colored pigmentation in a fruit or flower would automatically result in that individual and its offspring being noticed at the expense of other members of the plant population, giving the mutants a reproductive advantage. The same, simple process can explain a great number of cases throughout the animal world in which warm colors are used for attraction, particularly when they’re absent outside the mating season.

Brighter and redder colors attracting more initial attention than their opposites due to the structure of the visual sensory system, rather than evolving to meet some specific ecological purpose, can also explain their prominence in aposematic signals in animals, and why humans more often use these colors when getting our attention is important for safety reasons, such as in road signs, caution signs, warning labels, warning lights and emergency vehicles. Similar arguments can be made for the evolution of high-pitched sounds as warnings and sexual signals, both in animals and human culture.

One could take an anecdotal situation in which special attention to high pitch would have protected our ancestors, claiming for instance that it protected them against hissing or rattling snakes. A snake, however, has no interest in attacking a much larger animal. Its goal is to avoid a confrontation, and higher, louder sounds have always served this purpose better than quiet, low sounds due to the structure of animal auditory sensory systems. In other words, we didn’t evolve to notice high-pitched, loud sounds more than their opposites to avoid snakes, snakes evolved to express these qualities to avoid us and other animals that might pose a threat to them, and one could go so far as to suggest this is also the reason for their unusual length, assuming we attend to this quality more readily than roundness.

Attention to exciting qualities makes some amount of sense in the context of avoiding predators. It would be valuable to notice a large, loud, fast moving animal intending to eat us, but the fact that these qualities are generally salient would also pressure predators to make themselves small, keep quiet and move slowly as they hunt, at least until they’ve been noticed.

Notes

Perplexity’s answer to “Do heat, fluidity, dynamism, speed, disorder, brightness, warm colors, sound, loudness, high pitch, upwardness, outwardness, the left side, length, spikiness, large size, multiplicity, novelty capture attention more than their opposites coldness, solidness, stasis, slowness, order, darkness, cool colors, silence, quietness, low pitch, downwardness, inwardness, the right side, shortness, roundness, small size, small numbers, familiarity?

Some of the “hot/active” poles on your list do reliably capture more attention (motion, novelty, luminance/contrast, numerosity, left side), but others show weaker or more context‑dependent effects, and many are better described as “high arousal” rather than intrinsically attention‑capturing.

Motion / dynamism / speed. Visual search and interface work converge that motion (including flicker and abrupt onset) is one of the strongest bottom‑up attractors; static items are less likely to capture attention under equal conditions.

Novelty / change. Oddball designs show that deviant auditory events (novel sounds among standards) trigger an orienting response and impair performance on an ongoing task, supporting robust involuntary capture by novelty.

Brightness and contrast. Saliency models and behavioral data indicate that higher luminance and stronger contrast have greater bottom‑up salience than dim, low‑contrast regions, other factors held constant.

Warm colors (vs. some cools). Longer wavelength colors like red, orange, and yellow often produce higher physiological arousal and attentional priority than many neutral or mid‑wavelength hues, though effects depend on task and context.

Multiplicity / numerosity. Numerosity behaves as a basic visual feature; sets of many items can be detected pre‑attentively and act as salient “texture,” distinguishing them from regions with fewer items.

Left side. In neurologically typical adults, pseudoneglect produces a small but reliable leftward bias: people bisect lines to the left of true center and tend to initiate visual search on the left, indicating an inherent attentional advantage for left field over right.

Myths and Stories

More exciting qualities are typical features of evil characters such as monsters, and we’re more tolerant of the death and suffering of those who express them, to the extent that a character with the features doesn’t necessarily need to have commited any other offenses we would normally consider it fair to kill them for. Good characters, on average, feature more list 2 qualities than those who are evil. We want them to live and thrive, and it’s iteresting when they develop such that they express more list 1 qualities as the story goes on, as when a regular person becomes a superhero through an accident or magic and then defeats a villain. A modern case is the transition of Walter White from a chemistry teacher to a violent drug dealer in Vince Gilligan’s Breaking Bad.

Extreme expressions of list 1 qualities get people in trouble in myths and stories, when their punished by gods for obtaining fire, breaking rules, making too much noise, building too high or multiplying too much. Sometimes gods kill entire groups, or everyone, in massively disproportionate responses to these kinds of acts.

Perhaps the ultimate example of a contrast between a less exciting protagonist and a more exciting antagonistic is the story of Siddhartha Gautama and his adversary Māra. Siddhartha sits motionless in lotus position under the Bodhi tree at the central, “immovable spot,” touching the ground with his left hand in meditation. He’s renounced his royalty, removed the golden jewelry he’d worn previously, and shaved his head. As he sat, Siddhartha said (Campbell 2014):

Let my skin, sinews, and bones become dry, and welcome; and let all the flesh and blood of my body dry up; but never from this seat will I stir until I have attained the supreme and absolute wisdom!

Siddhartha is static, quiet, downward, round, central, dry and generally unaroused while Māra, Lord Desire, is commonly depicted with long hair, wearing a crown and extravagant jewelry, surrounded by fire, sitting on a “bellowing war elephant” with long, spiky tusks, accompanied by his sons Confusion, Gaiety and Pride and his shapeshifting daughters Lust, Delight and Pining (Campbell 2014). He wields arrows named “Exciter of the Paroxysm of Desire, Gladdener, Infatuator, Parcher, and Carrier of Death.” Māra and his companions express list 1 qualities in an extreme way, and represent the most arousing human emotions. Having attempted and failed to disrupt Siddhartha’s meditation with an arrow so powerful it had been used to ignite the sun, he tries unleashing a massive army of demons:

And immediately putting off his infatuating aspect as the Lord Desire, that great god became the Lord Death, and around him an army of demonic forms crystallized, wearing frightening shapes and bearing in their hands bows and arrows, darts, clubs, swords, trees, and even blazing mountains; having the visages of boars, fish, horses, camels, asses, tigers, bears, lions and elephants; one-eyed, multi-faced, three-headed, pot-bellied, and with speckled bellies; equipped with claws, equipped with tusks, some bearing headless bodies in their hands, many with half-mutilated faces, monstrous mouths, knobby knees, and the reek of goats; copper red, some clothed in leather, others wearing nothing at all, with fiery or smoke-colored hair, may with long, pendulous ears, having half their faces white, others having half their bodies green; red and smoke-colored, yellow and black; with arms longer than the reach of serpents, their girdles jingling with bells: some as tall as palms, bearing spears, some of a child’s size with projecting teeth; some with the bodies of birds and faces of rams, or men’s bodies and the faces of cats; with disheveled hair, with topknots, or half bald; with frowning or triumphant faces, wasting one’s strength or fascinating one’s mind. Some sported in the sky, others went along the tops of trees; many danced upon each other, more leaped about wildly on the ground. One, dancing, shook a trident; another crashed his club; one like a bull bounded for joy; another blazed out flames from every hair. And then there were some who stood around to frighten him with many lolling tongues, many mouths, savage, sharply pointed teeth, upright ears, like spikes, and eyes like the disk of the sun. Others, leaping into the sky, flung rocks, trees, and axes, blazing straw as voluminous as mountain peaks, showers of embers, serpents of fire, showers of stone. And all the time, a naked woman bearing in her hand a skull, flittered about, unsettled, staying not in any spot, like the mind of a distracted student over sacred texts.

Even this isn’t enough to distract Siddhartha, and Māra goes away defeated, his shoulders slumping in disappointment.

Visits of gods to the human world (theophanies) are regularly preceded or accompanied by increases of list 1 qualities and their conceptual relatives, in part because gods appearing without some kind of excitement feels inconsistent with their power and importance. In theophanies gods are typically accompanied by fire, clouds, storms, earthquakes, bright lights, thunder and, surprisingly often, by gangs of monsters, demons, angels or exciting animals.

Pairs of characters often differ with respect to excitement and primitive perceptual qualities, one of them being somewhat more disorderly, brighter, a different color, taller or thinner (longer) than the other, creating an amusing mixture of opposites, as when a hero is accompanied by a trickster. In stories with mythological twins there’s a theme in which they express properties at opposites ends of dualities such as immortal~mortal, evil~good or creation~destruction.

List 1 qualities are prone to being increased or exaggerated over time in stories, making them more exciting than they were to begin with. Characters increase in size, armies and death tolls get bigger, timelines or lives are extended, heroes get more heroic and monsters become more monstrous.

Humor

Shall I crack any of those old jokes, master, At which the audience never fail to laugh?

— Aristophanes, Frogs (Bartlett 2022)

Everything human is pathetic. The secret source of Humor itself is not joy but sorrow. There is no humor in heaven.

— Mark Twain, Following the Equator: A Journey Around the World (1897)

Insults

We use references to primitive perceptual opposites to express our displeasure with each other, linguistically and in gestures, and we dislike it when others use them against us. The examples listed below are in the same order as the qualities in lists 1 and 2, with each quality having various numbers of representatives. For instance, three insults (hot mess, flamer, a burnout) have heat as a conceptual relative, five have fluidity (airhead, windbag, lickspittle, milksop, piss ant, drip, mouth breather, blowhard), three have dynamism (jerk, creep, spaz) and so on. Some relate to more than one quality at once, such as “scum” and “sleaze,” which are both disorderly and fluid, or “tosser,” which is both dynamic and outward.

It’s worth noting that we regularly use such expressions entirely for amusement, some of them as much as we use them directly against each other as insults, and that under the right circumstances they can also be affectionate. Highly offensive insults having to do with parts of the body, behavior and other aspects of human life we consider vulgar are left out of the lists, although many of them could be included.

More exciting insults: a hot mess, hothead, flamer, burnout, airhead, windbag, lickspittle, milksop, piss ant, drip, mouth breather, blowhard, jerk (rapid movement), creep, spaz, crook, scum, sleaze, trash, crackhead, train wreck, slob, misfit, rotter, redneck, quack (high pitch), uptight, tosser, tosspot, prick (spikiness).

Less exciting insults: cold, cold-blooded, bonehead, numbskull, hard ass, meathead, knucklehead, shit for brains, stiff, thick, dense, deadbeat, slow, blockhead (order), square, dimwit (darkness), lowlife (down~dynamic), dipshit (down/solid), drop dead (down~static), you suck (inward), sucker (inward), dull, loser, halfwit (less).

Almost all of these expressions are literally nonsensical. They refer to characteristics that don’t actually apply to the people being insulted. “A hot mess” refers to a person who behaves unpredictably, hence the term “mess,” perhaps, but that person isn’t literally hot. Adding heat implies someone is more chaotic than if they were only a mess, which works based on the fact that we associate high temperature with disorder, and because the qualities add together in an unpleasant way. Likewise, “airheads” have nothing, literally, to do with air, “hotheads” don’t have hot heads, “crackheads” don’t have cracked heads, “stiffs” don’t differ in their physical consistency from non-stiffs, “deadbeats” aren’t dead, “lowlifes” aren’t low and “suckers” (inwardness) don’t suck.

Insults invoking perceptual opposites are skewed so that qualities from list 2 are applied to “lower” intelligence, as in the solidness of “bonehead,” “numbskull,” “meathead,” “knucklehead,” “shit for brains,” “thick” and “dense,” the stasis of “stiff” and “slow,” the downwardness of “lowlife” and “dipshit,” the darkness of “dimwit” or the numerical decrease of “halfwit.” Meanwhile, “higher” intelligence is assigned qualities from list 1: “quick wit,” “bright,” “brilliant” and “sharp.” The duality intelligent~unintelligent is aligned with primitive perceptual opposites from lists 1 and 2 because we understand more derived concepts in terms of earlier, preexisting psychological dualities.

The pattern carries over to longer insults such as “not the brightest bulb in the box,” linking low intelligence to darkness, “elevator doesn’t go all the way to the top floor,” linking it to lack of upwardness, “not the sharpest tool in the shed” (lack of spikiness), and “one card short of a full deck” (smaller quantities).

Insults like these are of interest in themselves from an aesthetic standpoint. We can use them as a joke and an insult at the same time. It’s remarkable how many portray a contrast between a quality from list 1 and its opposite from list 2 (slow~fast, dim~bright, dull~sharp, short~full), or couple a list 1 quality with negation, which is presumably less exciting than affirmation (not~sharp, not~full, not~bright, not~fast), or with containment, a type of inwardness: “not the quickest bunny in the forest” (dynamic inwardness), “not the brightest crayon in the box,” (bright inwardness) and “not the sharpest knife in the drawer” (spiky inwardness).

Differential Excitement in Humor

Some types of humor are structured explicitly as juxtapositions between more and less excitement. Sarcastic fake enthusiasm is this way, and so is fake indifference. Both strategies create a contradictory excitement differential between an experience and a reaction, and so do some of the most famous jokes.

Consider, for instance, Mark Twain’s Tom Sawyer arguing that painting a fence is exciting to trick other boys into doing the job for him, or Twain himself famously saying, after hearing the news he had died, that “The report of my death was an exaggeration,” later paraphrased, more memorably, as having been “grossly” or “greatly exaggerated.” In Aristophanes’ Wasps, it wouldn’t be funny if the old man Philocleon was addicted to something exciting, like sex or gambling. The joke is that he’s hopelessly addicted to jury duty. In the classic Norm Macdonald joke about a pig with a wooden leg, the pig is more exciting than the usual disabled pig, performing heroic acts on the farm, then the punchline contradicts how excited the farmer claims to be about the pig throughout the rest of the joke.

Cervantes’ Don Quixote plays on the fact that we expect a great knight to perform spectacular feats on the battlefield by replacing it with the sad scene of a man who thinks he’s performing such feats when he’s actually fighting a harmless windmill. Douglas Adams’ The Hitchhiker’s Guide to the Galaxy is humorously disappointing when the supercomputer Deep Thought works for seven and a half million years on the “Answer to the Ultimate Question of Life, the Universe, and Everything” only to give the answer as “42.”

Hierarchical Humor

On the assumption that high status is more exciting than low status, humor that inverts or disrupts the hierarchy incorporates differential excitement. This would include self-deprication and putting other people down, both of which we do for fun, and amusing scenarios in which a person, animal or object is elevated to a high position. Saturnalia does this with people, temporarily inverting the status of slaves and masters. Fables, puppets, shows and movies do it with animals, “The Frog Prince” being a famous example, and so do comics like Gary Larson’ The Far Side.

Universality

Although we tend to think of every humorous event as unique and independent, they must be related in some way because we respond to them automatically and universally with laughter. We don't laugh at just anything, and more often than not we agree about what's humorous, or at least meant to be, so there’s something we all recognize in humor, despite its diversity, something that makes it perceptually and psychologically different from seriousness.

Whatever it is that funny things have in common, the nature of laughter: loud, often high-pitched outbursts punctuated by short periods of silence, implies contradictory stimulation in the brain, in that high sounds and silence are opposites. Laughter mixes these qualities in intricate ways, and so do music, song and language. This is evidence of an aesthetic origin of laughter and humor, which is intuitive, although most biologists would probably say both phenomena evolved as a social device that increased survival, although we can’t currently imagine the reasons. They might say laughter’s purpose is demonstrating to a potential mate that we have the capacity to utter a range of sounds, but this could be accomplished in any number of alternative ways, and the advantage to a mate of having a way to gauge this ability doesn’t come close to justifying the consistency of human laughter, the scale on which it occurs, or the fact that it’s practiced so widely outside the context of courtship.

The Fluidity of Humor

The word “humor,” from Latin meaning “moisture,” was used for centuries to describe various fluids, as with the concept of humorism in which behaviors were thought to arise from fluctuation in the levels of four particular types of fluids in the body. This suggests jokes, like “flowers” compared to leaves, come across as fluid-like compared to seriousness, boringness or “dryness.” The connection is a clue to how funny things are special. The expression “dry humor,” for jokes delivered in a serious tone, is another indication we relate them to fluids (and seriousness to dryness). “Deadpan,” with a meaning similar to “dry humor,” referring literally to the stasis of death and the solid inwardness of a pan, reflects that by default we relate jokes to fluidity, dynamism and outwardness, and seriousness to their primitive perceptual opposites.

Humor and Primitive Opposites

In addition to fluidity, we associate jokes with heat, disorder, speed, brightness, upwardness, outwardness and spikiness, as in “on fire” (of a comedian), “a sick burn,” “broke as a joke” (jokes=disorder), “cracking me up” (jokes=upward disorder), “wisecrack”(jokes=disorder), “busting up” (jokes=upward disorder), “bust a gut,” “dirty joke,” “break out in laughter” (jokes=outward disorder), “break the ice,” “pull a fast one,” “a quick wit” (jokes=speed), “make light of,” “uproarious,” “out of control,” “that's going too far” (jokes=outwardness) and “a sharp wit” (spikiness).

“Breaking the ice,” socially, humorously or otherwise, implies something is cold and hard about reality, independently of the common phrase “cold hard truth,” and in accordance with fantasy being, oppositely, like heat and fluidity. Consider, also, that we say extreme seriousness is “dead” and “down to earth,” or static, downward and solid. We also tell each other to “shape up,” and call overly serious people “squares,” as though they’re related to simple geometric order. The language of humor thus demonstrates universal unconscious associations between fluidity, disorder, dynamism, and the directions up and out, while that of seriousness demonstrates associations between coldness, solidness, stasis, shape and downwardness.

Funniness often represents a moment of departure from seriousness and reality into chaos and fantasy, contradicting associations of qualities within categories of excitement, making normal language and interactions more complicated and enjoyable than they would be otherwise. The reversal of social norms (politeness, manners) in jokes could be interpreted as such a disruption, undermining less exciting, familiar, expected behavior with more exciting novelty, unpredictably and contradiction. Disorder on its own can be funny, especially when it’s harmless and in orderly contexts such as formal settings, as the comedian Steve Martin pointed out.

Chaos in the midst of chaos isn't funny, but chaos in the midst of order is.”

— Steve Martin (Zhang 2023)

Assuming chaos is more exciting than order, the combination chaos/chaos is more exciting than the mixture chaos~order, while the combination order/order is relatively boring, and also not funny. Thus, in this respect humor, unquestionably an aesthetic phenomenon, is describable as a mixture of more and less excitement, supporting the present thesis.

The Great Chain of Being

We shall be free; the Almighty hath not built
Here for his envy, will not drive us hence:
Here we may reign secure, and in my choice
To reign is worth ambition though in Hell:
Better to reign in Hell, than serve in Heaven.

—John Milton, Paradise Lost (2020)

The Great Chain of Being, a popular concept throughout history going back at least to Ancient Greece, might be thought of as a vertical spectrum with phenomena representing qualities at the more exciting ends of primitive perceptual dimensions (list 1) at the top and those from the less exciting ends (list 2) at the bottom.

This assumes fluid-like spirits excite us more than minerals, that animated beings like animals excite us more than inanimate objects, that brightness does so more than darkness, and that it’s more exciting to be eternal than lifeless, powerful than inconsequential, and located in the heavens than in the ground. All of this seems reasonable based on intuition, and it’s also backed up by patterns in language and gestures.

Gods and angels, the highest characters in the Chain, are said to be purely spirit, or nonmaterial, like a fluid. Minerals, at the bottom, are totally material and solid, while humans and organisms are in the middle, a soft mixture of these conditions, partly spirit and partly matter, or both fluid and solid at the same time, like a liquid crystal. Solids themselves are ordered according to brightness, with gold above silver and silver above lead. The very bottom of the Chain, below minerals, is absolute nothingness.

Dynamism is absent in the minerals at the bottom of the Chain, but present in plants, and increases from the “lower” to “higher” animals. Elevation increases as well, in that gods and angels are usually positioned spatially above humans and the earth, descending occasionally for reasons such as delivering a message directly to humanity, getting revenge or retrieving someone from hell. Vitality also increases with height, from the nonliving to the living to the immortal.

Not every pair of opposites in the Chain is arranged so that the more exciting quality describes higher components. Order, particularly its conceptual relatives perfection and lack of change, are understood to be greater in the gods than humans. Demons are below angels despite being evil and presumably disorderly by comparison, and the Bedlam beggar represents a lower, more chaotic stage of humanity adjacent to the beasts. Minerals are the least perfect objects, and nothingness is the least perfect nonexistent thing, although the word “perfection” in this context probably means something closer to fullness of existence than to our contemporary idea of order. Light and heat aren’t official participants in the hierarchy, but they’re more associated with the upper reaches, and multiplicity seems to fall off from the middle in both the upward and downward directions.

Within animals, those that are larger, more dynamic and have blood are above smaller, slower, “bloodless” types. Lions and elephants are the kings of beasts, and sessile animals, shellfish and invertebrates populate the lowest ranks. Among celestial bodies, the sun is above the moon, but below the “unmoved mover” and ultimately the Empyrean, or highest heaven, derived from Greek words meaning “in the fire,” “fiery” or “region of pure fire and light.”

Dominance is maximized by the gods at the top, who have power over angels, and both types of beings have more power than kings and royalty, who rule over common people, who themselves dominate animals, who dominate plants and minerals. This follows the universal human conviction that there’s a vertical difference between the superior (or dominant) and inferior (or submissive), which is also built into language and words, “super” in “superior” meaning “above, over, beyond” (up and out), and “sub” in “submission” meaning “under, below, beneath.”

Calling it a chain implies continuity, and various intermediate beings fill in the gaps between levels, such as demigods with less vitality than gods and more than mortals, demons with more power than people and less than angels, or plant-like animals with less of a soul than animal-like animals but more of a soul than a rock.

The upper section of the Chain is mythical, invented and adopted by humans, and this is important to consider because otherwise it would be a fairly accurate description of reality, and therefore less of an aesthetic phenomenon. The mythic section makes us inferior, when we could have placed ourselves at the top. Gods, angels and demons don’t need to be part of the Chain, and they don’t need to be made of pure spirit. No one noted their properties and placed them above us to represent observable reality. They were added and assigned a fluid-like form for our satisfaction, making the Chain as a whole of greater interest from a psychological point of view than it would be otherwise. Without gods it would only be a partial spectrum of differentially exciting opposites. Fluidity would top out about halfway to its full realization in spiritual beings. Mediocre humanity, with its limited control of the universe, would be the pinnacle of power, and immortality, or infinite animation, wouldn’t exist at all.

We’re amused when the Chain is disrupted by characters moving out of their proper positions. They might be promoted or demoted, travel from one link to another and come back, or split into two and go both up and down at the same time, as when a demon is thrown down to Earth, a god becomes mortal, a statue comes alive, a frog turns into a prince, a king is stripped of his crown, a base metal is alchemized into gold, a hero goes to hell and back, a man dies and gets resurrected, angels descend and ascend a ladder between the divine and human realms, or a soul exits a body and floats away. To the extent that there’s a continuous excitement differential from one end of the Chain to the other, such disruptions are mixtures of more and less exciting things.

Natural Events

Natural events fall into more or less exciting categories depending on their content with regard to lists 1 and 2. The summer, because it’s relatively hot and bright, is more exciting than the winter. The summer solstice is naturally more exciting than the winter solstice. The relative hotness and brightness of the sun makes it more exciting than the moon, and the full moon is more exciting than the new moon. Spring is more exciting than fall, morning is more so than evening, noon more so than midnight and so on. Because of the position and apparent motion of the sun, in the northern hemisphere south should be more exciting than north, and vice versa from the southern hemisphere, while east should be more exciting than west everywhere.

Astronomical cycles appear to cause cycles of arousal in animals that result in important biological rhythms related to sleep and reproduction. On average, any animal living above ground is going to be more excited by more light in the middle of the summer and less so by less light in the middle of winter. For humans, above the equator, the yearly cycle of brightness and temperature probably has something to do with the placement of certain exciting celebrations in darker, colder seasons, gods being born around the winter solstice, for instance, or celebrating Halloween, the most evil holliday, in the fall.

Jesus said ‘I am the light of the world.’ And they just loved that image of the light of the world becoming visible on the darkest day of the year on the winter solstice. That image spoke to them very deeply. And we see this come up repeatedly in Christmas sermons, in other topics regarding Christmas. And I think that that was the factor that made December 25th win out over other possible dates. There was this beautiful, from their perspective, profound symmetry and imagery involving this date.

— Thomas C. Schmidt, “Why Is Christmas on December 25th?” (2025)

Excitement and Eysenck's Mechanism of Personality

Eysenck's theory of introvert versus extrovert behavior and arousal can be used to determine the relative excitingness of various primitive perceptual opposites.

Currently, there are few studies directly assessing the relationship between extraversion and the cortical arousal system in the context of varying stimulations but data available so far are remarkably consistent with Eysenck's model.

— Mitchell and Kumari (2016)

According to Hans Jürgen Eysenck's arousal-based mechanism of personality type (1952, 1963), extroverts have lower inherent activity in the brain, and they compensate for the resulting lack of excitement they feel by favoring more arousing experiences and stimuli, while introverts, with higher inherent brain activity, compensate by favoring lower arousal. There's an important aesthetic component to this idea in that the distinction between types, which were first proposed by Carl Jung in Psychologische Typen (1923), is based on the fact that they have slightly different preferences with respect to certain primitive perceptual opposites.

One might think, initially, that extroverted behavior is the result of a higher default arousal level, and the opposite for introverted behavior, that it's a reflection of relative tranquillity in the brain. Instead, the theory has the same property of contradiction that occurs generally in aesthetic phenomena: low arousal is countered by high arousal and vice versa. It's also conveniently aligned with the idea of aesthetic reflex, that opposite qualities induce a desire for each other. Too much noise, for instance, seems to increase the appeal of silence, or motion of stasis, brightness of darkness, outwardness of inwardness and so on, such that satisfying patterns can be created by alternating instances of these and other opposite qualities.

Eysenck's mechanism appears to support a physical version of mental representation, in that outward, perceptually exciting things translate into (are represented by) comparable neurological excitement in the substance of the brain, with less exciting things translating into less excitement, maybe none in the total absence of a stimulus (darkness, silence). This means the brain alternates between states of higher and lower temperatures, and therefore thermophysical conditions, in response to various stimuli over short periods of time, in addition to doing so diurnally and as it cycles through the stages of sleep. Thermal variation in the brain is thus a notable biological feature in a number of contexts and over a wide range of timescales, reason to suspect it plays a significant role in how the mind works.

Assuming Eysenck is right, it's implicit that neurological activity increases more in response to perceptual qualities preferred by extroverts than those preferred by introverts, providing a method for sorting stimuli into more and less exciting categories, independently of the linguistics-based method by which the same can be done with less effort.

Extroverts have been found to prefer high chroma (Pazda et al. 2018) and "warmer, more intense" colors (Robinson 1975, Choungourian 1967) when compared to introverts, who prefer "cooler, calmer" colors. By "warm," researchers mean red, orange and yellow; by "cool" they mean green, blue and purple. This is an example of temperature being applied, mysteriously, to qualities that don't actually express heat, coldness or warmth. No color is hotter or colder than any other. Red isn't actually warmer than blue. It's also no more intense, in itself, and blue isn't actually calmer than red. We use these terms of action and temperature to describe colors due to automatic psychological connections. Redness, heat and motion feel somewhat similar to each other, and so do blueness, coldness and stasis.

The results of hue heat experiments (see Ziat 2016) can be interpreted as showing that we unconsciously associate red with higher temperatures and blue with lower temperatures. We already knew this, however. It's built into language and culture, the latter in that red signals heat and blue signals coldness. In this case, at least, language can be used to predict the results of experiments because it reflects unconscious, universal associations. One proposition given in the main story is that this works very generally, that experiments will independently demonstrate associations between idiomatic heat and physical heat in almost all cases. Redness probably makes a person feel slightly hotter, and so do spices, anger, sex, rapid motion and other things we call hot for no apparent reason. What these things have in common is that they excite the brain more than their opposites, or their absence, and this is a much simpler explanation of where the associations come from than the unlikely scenario in which we all learn them from experience and happen to arrive at the same conclusions. In any case, putting extrovert warm color bias together with Eysenck's theory leads to the conclusion that brighter and warmer colors are more arousing to the nervous system than darker and cooler colors, which makes sense given the way we use the former to capture attention. This should also work the other way around. If there's reason to think heat is more exciting than coldness, we should predict extroverts to prefer a slightly hotter environment than introverts.

That extroverts choose outwardness over its opposite inwardness more often than introverts is clear enough from the terminology "extro" and "intro," and from definitions of the personality types. From Oxford Languages, via Google, an extrovert is "an outgoing, overtly expressive person," indicating such a person prefers and engages in more outwardness and dynamism than an introvert, defined as "a shy, reticent person." From Oxford Dictionary, extrovert means "a person who is predominantly focused on external things or social interaction rather than on internal thoughts and feelings" and introvert means "predominantly focused on internal thoughts and feelings rather than on external things or social interaction, often characterized as being quiet or withdrawn."

This serves to highlight the significance of outwardness and inwardness to the mind, that we think of these as fundamental opposites, with outward being more exciting than inward. The aesthetic value of out and in is easily demonstrated. They might be the most commonly juxtaposed directional opposites in aesthetic material, with hundreds of examples in language, poetry, mythology and elsewhere, perhaps because they're easy to make reference to and they matter a great deal to horizontally interacting animals, but also because the idea of out versus in is applied to more than one dimension of perception: near versus far, edge versus center and to shape, describing the inward and outward aspects of an object.

The biological interplay between outwardness and inwardness is a much bigger subject than human personality. In fact, biologists will eventually conclude that a universal interest in inwardness mixed with outwardness is largely responsible for the shapes of animals. Sexual selection in favor of this mixture is the reason that inward parts of the body are so generally coupled with outward features throughout the animal kingdom, and artificially so in humans. This means an understanding of the difference between out and in originated very early in the psychological evolution of animals.

The extreme importance of in and out is reflected in the structure of language, where the qualities appear in expressions such as "entertainment," "interesting," "expression" or "extreme importance." They play a more extensive linguistic role, it seems, than other directional opposites such as up versus down or left versus right. Extroverts probably have biases with regard to all directional dimensions, predictably for upwardness and the left side, which is automatically associated with change, disorder and other higher excitement qualities, including outwardness, as in "came and left."

Extroverts tolerate noise better than introverts (Geen 1984, Standing et al. 1990, Belojevic 2001, Moradi et al. 2019), suggesting noise is more exciting than silence. Again, this is what we would expect on account of the way we use sound, and particularly loudness, to get attention. Noise feels a little hotter, redder, brighter and outward than silence, probably the reason we use "loud" as a term for gaudy coloration, and perhaps for correspondences between words like "yell" and "yellow" or "shout" and "out." Silence feels cooler, darker, bluer and more inward. High pitch can most likely be added as a relative of more exciting qualities, and to the list of qualities extroverts prefer a little more of than introverts.

Most interestingly, at least one study has shown, by a variety of approaches, that extroverts have a detectable preference for fluidity and introverts for solidness (Oishi et al. 2015):

In five studies, we tested the link between personality and geography. We found that mountain-lovers were more introverted than ocean-lovers (Study 1). People preferred the ocean over mountains when they wanted to socialize with others, but they preferred the mountains and the ocean equally when they wanted to decompress alone (Study 2). In Study 3, we replicated the introversion - extraversion differences using pictures of mountains and oceans. Furthermore, this difference was explained in part by extraverts' perception that it would take more work to have fun in the mountains than in the ocean. Extending the first three studies to non-students, we found that residents of mountainous U.S. states were more introverted than residents of flat states (Study 4). In Study 5, we tested the link between introversion and the mountains experimentally by sending participants to a flat, open area or a secluded, wooded area. The terrain did not make people more introverted, but introverts were happier in the secluded area than in the flat/open area, which is consistent with the person - environment fit hypothesis.

Extrovert bias for fluidity means we can think of it as more exciting than solidness. The fact that fluid versus solid appears to constitute a basic pair of opposites in the context of personality theory is reason to consider it a primitive perceptual duality like we do bright versus dark, hot versus cold or dynamic versus static. More reason to do so comes from how commonly aesthetic phenomena in biology (flowers, long hair, ornamental feathers and fins) and human decorations (spirals, dresses, flowers) mimic the essence of a fluid.

Eysenckian personality theory thus allows us to construct lists like the one below, which shows more exciting, extrovert-preferred qualities first, to the left of a tilde, coupled with introvert-preferred qualities, given to the right. Others can be added, tentatively at least, based on the contents of extrovert/introvert questionnaires (Eysenck and Eysenck 1968, 1975) which ask about such things as how many other people someone likes to be around, attending parties, being active and being okay with disorder as opposed to being alone, orderly and moving slowly, such as "Would you be very unhappy if you could not see lots of people most of the time?," "Can you usually let yourself go and enjoy yourself a lot at a lively party?," "Are you slow and unhurried in the way you move?," "Are you bothered by disorder" and "Do you dislike imperfect work." That these questions effectively sort subjects into extroverted and introverted categories implies that many~few, active~inactive and disorder~order are differentially exciting opposites.

Excitement opposites: warm color~cool color, fluid~solid, active~inactive, disorder~order, sound~silence, loud~quiet, out~in, many~few.

See Appendix 1 for thousands of examples of how these and other pairs of primitive perceptual opposites are also juxtaposed in aesthetic material, probably not by coincidence, in that the same neurological properties responsible for personality types seem to be involved in aesthetic decisions. Evidence from various fields can be used to illustrate that heat, length, spikiness, larger size and upwardness are more exciting than their opposites, so it's predictable that experiments will eventually reveal extroverts also tolerate/prefer these qualities slightly more than introverts, who should prove to be more partial to coldness, roundness, smaller size and downwardness.

Regardless of whether someone is an introvert or extrovert, less exciting things should be preferable when the brain is aroused beyond some level, and the preference should shift to more exciting things when the brain is less aroused and below that level. Presenting a person, even an extreme extrovert, with too much sound, action, brightness, fluidity and other excitement will eventually induce a preference for the opposites of these qualities. In reality, of course, people normally fall somewhere in between extreme extroversion and introversion. Most of us probably aren't far from what psychologists call ambiverts, with moderate baseline arousal and preferences.

All of this points to the existence of an optimal arousal point, an ideal excitement level or physical condition in the brain, a Goldilocks-like state of intermediacy that corresponds to feeling satisfied, and this is in line with the Yerkes Dodson law (1908), which states that performance is maximized by moderate levels of arousal. It's also reminiscent of the many philosophical and religious concepts that advocate for moderation.

If this process of approaching an optimal point happens so widely, influencing personality and performance, determining likes and dislikes, and corresponding to satisfaction, perhaps the same sort of process is happening in an aesthetic context, with oppositely exciting stimuli countering the influence of each other to create an amusing effect because they also lead to an optimal, moderate amount of excitement.

To summarize, Eysenck's personality theory mechanism, which has been "remarkably consistent" with data, offers an empirical, fairly indisputable approach to sorting perceptual qualities according to arousal. It also supports other aspects of the idea of thermoaesthetics, in that it involves contradiction and complexity of differentially exciting opposites, mental categories, the ideas of aesthetic reflex and physical mental representation, and also aesthetic indifference, since non-optimal levels of excitement in the brain can evidently be compensated for by any stimulus that pushes it in the optimal direction.

Temperature

Language and Temperature

When we call people hot-tempered, heated, fired up or furious, and agree that these are appropriate labels, it can’t be because we’ve observed an outward connection between anger and heat, or fire, because in reality angry people don’t appear to be hotter than people who are content. We say “lower the temperature” not because it’s actually increased in a situation where tempers are high, but because we associate lower temperatures (and downwardness) with peace and calm. The same goes for expressions like those below, which indicate a connection between heat, passion and danger in addition to anger.

Heat idioms: temper tantrum, don't tempt me, hothead, heated argument, a hotbed (danger), a hotspot (danger), inflammatory (exciting), things are heating up (exciting), playing with fire (danger), inflame the situation (danger), a conflagration, steamed (hot/fluid), blow a fuse (anger), a short fuse (anger), burning with rage (anger), burning desire (passion), making sparks (sexual), have the hots for (passion), in heat (sexual), hot stuff, a hot date (romantic partner), a flame (romantic partner), a smoke show (fluid/attractive), steamy (hot/fluid/sexual), the heat of passion (sexual), five-alarm fire (many/loud/high pitched/bight/hot), hot damn (exciting), hot diggity dog (exciting), the heat is on (exciting).

In no case is there any heat, fire, burning, flaming, smoke, steam or other any other heat-related or fluid-related quality actually present in the phenomena to which we apply these expressions. Each one should be thought of as providing its own independent evidence that heat is unconsciously associated with excitement. We wouldn’t think to label anger and passion in the opposite manner, although a poet or comedian might do this deliberately, violating our expectations to be poetic or funny.

Some of the given expressions are of particular interest because they refer to fluids and fluidity, as in flames, water, steam, spit, blood and smoke, in addition to heat, suggesting fluidity is like heat in being exciting. Some are notable because they couple heat with something unexpected, as with a bed in “hotbed,” a head in “hothead,” inwardness in “in heat” and digging in “hot diggity dog.” These can be thought of as mixtures, with the ideas of a bed, a head, inwardness and downwardness counteracting the excitingness contributed to the expression by heat.

The link between spiciness and heat further illustrates that we don’t learn associations between perceptual opposites and our feelings by making outward observations. We hardly imagine there to be a distinction between the heat of spicy foods and actual heat, although the two things have nothing to do with each other perceptually. According to Perplexity:

Spicy foods mostly feel hotter rather than literally heating the mouth or brain much more than bland foods at the same physical temperature, though they can cause a small real rise in body temperature and blood flow.

Spiciness and high temperature share an association with excitement, which is why we say “spice it up,” and “the spice of life.” Physically, the two are probably related in the mind because they produce a greater increase in brain temperature than coldness and blandness (flavorless/unexciting), the same reason anger and heat are related.

It’s predictable, based on a hypothetical association of qualities in list 1 with excitement, that reasearch will eventually converge on the result that all languages, cultures and humans tend to describe anger as hot, fluid and disorderly. According to Tien (2022):

Recent research shows that metaphors and metonymies of anger in Indo-European languages have striking similarities with few variations. The English and Hungarian languages share significant similarities in metaphors of anger (Kovecses 2000, 2005). One minor difference is that while English makes use of the whole body for metaphors, Hungarian has 'head' as a container that can hold the hot liquid in the metaphor Anger is a hot fluid in a container. Soriano (2003) investigated the metaphorical models of anger in English and Spanish … She found that there are considerable commonalities in the cognitive model of anger in both tongues. … both English and Spanish conceptualize the effects of anger on the person as 'boiling' or 'burning'. Nonetheless, further elaborations show that Spanish people make use of 'get fried' linguistic expression as compared to the 'stew' manifestation in English due to the cultural preferences in cooking culture. Conceptual metaphors of anger were also contrastively analyzed in English, French, and Greek discourses based on the comparable corpora in psychology, psychiatry, and psychotherapy (Constantinou 2014). She found that the three languages share the conceptual metaphors Anger is a hot fluid in a container, Anger is fire, Anger is insanity, and Anger is an opponent in a struggle. … A comparative study of English and Persian (Abbasvandi & Maghsoudi 2013), which is a more distant language than the aforementioned tongues and cultures, also indicates a tendency in universal features of anger metaphors. Both languages have common conceptual metaphors of anger as Anger as a fluid, Anger as heat/fire, Anger as an opponent, and Anger as insanity.

Lower temperature, less excitement, and lack of interaction being related in the mind is apparent in the origin and popularity of expressions such as “chill out,” “take a chill pill,” “cold-hearted,” “stone-cold,” “simmer down,” “freeze out” and “frigid.” Some of these also refer to solidness, inwardness and downwardness, which, like coldness, we’re tempted to mention in depressing situations, even though they don't actually apply in the observable world. Moderate, desirable social interactions are accordingly assigned a moderate temperature: “even-tempered,” “warmhearted,” “warming up to,” “a warm welcome” and “a thaw in relations.” Expressions of friendliness as warmth can be thought of as reflections of the fact that, from our perspective, physical warmth is agreeable while heat and coldness are not.

More and Less Excitement in the Brain

Every sensory dimension seems to be structured such that a quality at one end of the dimension is more arousing than the other, suggesting this structure is somehow convenient in organic material for the purpose of receiving and analyzing signals, and that sensory systems are tied to a mechanism of perception that also relies on some sort of differential excitement for the purpose of distinguishing opposite inputs, similar to the way a liquid crystal thermometer tells temperature, rather than the way a computer does calculations.

The parallels between a brain and computer are well known, but the differences are often ignored. Computers don’t forget things, like brains do. They don’t make mistakes, or perform false calculations for fun. Most importantly, they’re solid, while brains are mostly fluid, with a large liquid crystalline component (e.g., membranes, myelin) and only a small section of solid, crystalline matter, at the center in the pineal gland. Unless one is inclined to believe that liquid water in the brain is the sentient component, we should assume it’s the liquid crystalline portion that contributes most significantly to consciousness, a reasonable assumption on account of the fact that animals enter an unconscious state as the brain becomes either too cold or too hot.

Liquid crystals are useful as thermometers because they respond to temperature variation more continuously and readily than matter in solid states. Their molecules gradually gain energy: vibrating, traveling and spinning faster and moving out of alignment as they heat up, then they gradually gather back together into regular arrays and slow down as they cool, so there’s a clear, high resolution excitement differential between hotter and colder conditions. Because temperature is an abstract concept created by humans, this differential is more accurately described as a set of thermal opposites, which, particularly in the case of a liquid crystal, could be denoted as follows.

Thermal opposites: fluid~solid, dynamic~static, fast~slow, disorder~order.

That these are simultaneously physical opposites in the animal brain, psychological opposites in the mind, behavioral opposites in animals and cultural opposites in human societies and language is unlikely to be a coincidence. Organic material, bodies, brains, consciousness and sensory systems evolved in accordance with the physical laws of temperature and states of matter, so it’s hardly unthinkable that they would be incorporated into the products of evolution, or appropriated to serve certain biological purposes.

Liquid crystallinity playing a role in the emergence of animal consciousness and psychology is probably the ultimate reason we associate heat with excitement and high arousal emotions, and list 1 qualities with each other. It doesn’t necessarily follow, in traditional scientific or philosophical perspectives, that the opposites of the thermal qualities in list 1 (coldness, solidness, stasis, order) would be associated with lower arousal in the mind. That they are is evidence for the thesis that small scale structure and thermal fluctuations in the brain have large scale effects in the realms of animal behavior and human culture, which is the argument Esther Leslie makes in Liquid Crystals: The Science and Art of a Fluid Form.

This goes for the non-thermal qualities as well. It doesn’t necessarily follow from red being arousing that blue should be the opposite. Based on current theories, there’s no particular reason to expect the two colors not to be equally exciting, or even to predict they would be thought of as opposites. High pitch doesn’t necessarily need to be more exciting than low pitch. They could just be different types of sound with an equally exciting effect. The perception of upwardness could have evolved to be opposite to downwardness, in response to whatever survival or reproductive purpose understanding the difference might serve, without the simultaneous evolution of an arousal differential between the qualities, and much the same can be said for other pairs of primitive sensory opposites, especially left versus right and long versus round.

Thermal sensitivity of the kind that characterizes liquid crystals could be coupled with peripheral structures that receive light or sound waves or other types of information from the environment and translate them into more or less thermal excitement in various pathways through the brain, a conceivable prospect because neurological membranes are liquid crystalline, and because impulses generate heat as they propagate through networks of nerves. This way it wouldn’t be necessary for an entirely new, complicated type of infrastructure to evolve to support each new sensory dimension; the core of the system would already be in place. From this perspective, the brain isn’t soft only as a side effect of its chemistry or other attributes. It evolved to be soft, or liquid crystalline, in part because matter in this state is more sensitive to incoming signals than purely liquid or crystalline matter.

While the differential excitement isomorphism between matter in the brain and animal arousal might be somewhat unsurprising, and could potentially be explained by survival benefits, there’s a more mysterious structural isomorphism between thermal opposites and aesthetic material, which can’t be predicted by natural selection. Brain softness also seems to provide a mechanism for preferences, in that they could be based on small scale thermal fluctuations around a physical condition in the brain that happens to be conducive to or optimal for consciousness.

The drug Ecstasy produces a feeling of euphoria and causes a rapid and sustained increase in the temperature of the brain. Brown and Kiyatkin (2004) warn that the use of this drug, coupled with exciting social interactions, like partying, especially at high ambient temperatures, can cause death by pushing the brain above its lethal thermal limit, as was the fate of the most of the rats in their experiment. Methamphetamine produces a persistent temperature spike in the brain, greater than for body muscle, of 4 degrees Celsius for up to 4 hours in rats (Brown et al. 2004). Methamphetamine combined with social interaction, which itself increases rat brain temperature by 1.5 degrees Celsius, can also push a brain beyond its limit of about 41 degrees Celsius and kill an animal.

Male mouse brains heat up at the sight of a potential female behind a barrier, heat up more when the barrier is removed so they can interact, peak at ejaculation, and then cool down rapidly for a period before more casual mouse interactions resume (Kiyatkin and Mitchum 2003). Brain tissue temperature in all areas was found to increase faster than that of muscle. The authors say their findings suggest brain temperature is “a powerful factor affecting various neural functions and an important part of brain mechanisms underlying motivated behavior” (Kiyatkin and Mitchum 2003).

Angry and aroused male mice (Kiyatkin 2010), aroused male zebra finches (Aronov and Fee 2012), and chimpanzees observing aggression between other chimps (Parr and Hopkins 2000) experience brain temperature spikes. Anger levels are magnified by exercise, which itself increases brain temperature through metabolic heat production:

After one finishes exercising, the sympathetic nervous system returns to its normal level of activation at a measured pace; thus, for some time after the completion of exercise, one is in a state of decreasing neural arousal. If one is angered during this period, the neural arousal “piggybacks” the arousal generated as the result of becoming angry, causing the anger to be inappropriately intense. This piggybacking of residual neural arousal on subsequently induced emotional arousal, which Zillmann calls the excitation-transfer process, provides a plausible explanation for the human tendency to overemote occasionally about trifling matters or events (Optimal Arousal Theory 2026).

Dolf Zillmann’s (1983) excitation transfer process might be responsible for the apparently overlapping excitement when we experience two or more list 1 qualities at the same time or in close proximity. This would justify the system adopted here of calling the pairing of two or more qualities from one mental category a combination and a pairing from opposite excitement categories a mixture.

Heat would seem to be a good candidate for the mechanism by which excitation is transferred from one area of the brain to another, because it’s correlated with excitation and could flow naturally between the areas, especially if they’re close together.

The experience of an exciting stimulus leaves residual excitement behind in the brain for some period of time, during which the introduction of another exciting stimulus will cause a greater overall arousal level than what would normally be caused by the second stimulus alone. Recent increases in arousal are “misattributed” to current events. Heat transfer again makes sense as a mechanism in this case because heat is dissipated gradually.

Kiyatkin et al. (2001) showed that the brains of rats heat up rapidly by about 1° C when they’re exposed to novelty, social interactions or the stress of being pinched on the tail, and that the heat is “emotional,” generated by neuronal activation in the brain itself rather than being transferred from other internal parts of the body.

The extremely soft and liquid crystalline nature of matter in the brain allows it to cycle between a higher temperature and therefore more fluid, disordered, dynamic, expansive and conscious condition, during the day for instance, and an unconscious, colder and inevitably more solid, orderly, static and compact condition, such as at night when we sleep. Throughout sleep the brain also cycles thermally through a hotter, dreaming, rapid and random eye movement phase and a colder, slower, dreamless phase with steadier and more orderly eyes.

Knowing that, for whatever reason, the brains of animals have evolved to alternate universally between approaches to fluidity and solidness in contexts such as the sleep wake cycle, or between contentment and anger or passion, it’s not unthinkable that the brain would fluctuate thermally in response to more and less exciting stimuli in general. Any stimulus that activates neurons, causing them to “fire,” will result in an increase in brain temperature and a temporary change away from a relatively crystalline state in the direction of a liquid state, with removal of the stimulus or the introduction of a less exciting one corresponding to the opposite transformation, toward crystallinity.

Thermal variation in the brain appears to be a very important feature, not the inconsequential side effect of a computer-like information processing system. The fact that extremes of the given thermal opposites are detrimental to the structure, integrity and operation of the brain is probably related to the way we find the same extremes undesirable psychologically. We prefer experiences that mirror the physical situation of neurological material, with moderate degrees of order, disorder, stillness, motion, fluidity and solidness. One implication of this perspective is physical mental representation, the idea that we recognize outward disorder by way of disorder in the brain, heat by way of heat, fluidity by fluidity, solidness by solidness, geometric order by neurological order and so on, as claimed by Empedocles long ago, and recently by Esther Leslie (2016).