Evolutionary Psychology

Like “IRC chat” or “TCP/​IP pro­to­col”, the phrase “re­pro­duc­tive or­gan” is re­dun­dant. All or­gans are re­pro­duc­tive or­gans. Where do a bird’s wings come from? An Evolu­tion-of-Birds Fairy who thinks that fly­ing is re­ally neat? The bird’s wings are there be­cause they con­tributed to the bird’s an­ces­tors’ re­pro­duc­tion. Like­wise the bird’s heart, lungs, and gen­i­tals. At most we might find it worth­while to dis­t­in­guish be­tween di­rectly re­pro­duc­tive or­gans and in­di­rectly re­pro­duc­tive or­gans.

This ob­ser­va­tion holds true also of the brain, the most com­plex or­gan sys­tem known to biol­ogy. Some brain or­gans are di­rectly re­pro­duc­tive, like lust; oth­ers are in­di­rectly re­pro­duc­tive, like anger.

Where does the hu­man emo­tion of anger come from? An Evolu­tion-of-Hu­mans Fairy who thought that anger was a worth­while fea­ture? The neu­ral cir­cuitry of anger is a re­pro­duc­tive or­gan as surely as your liver. Anger ex­ists in Homo sapi­ens be­cause an­gry an­ces­tors had more kids. There’s no other way it could have got­ten there.

This his­tor­i­cal fact about the ori­gin of anger con­fuses all too many peo­ple. They say, “Wait, are you say­ing that when I’m an­gry, I’m sub­con­sciously try­ing to have chil­dren? That’s not what I’m think­ing af­ter some­one punches me in the nose.”

No. No. No. NO!

In­di­vi­d­ual or­ganisms are best thought of as adap­ta­tion-ex­e­cuters, not fit­ness-max­i­miz­ers. The cause of an adap­ta­tion, the shape of an adap­ta­tion, and the con­se­quence of an adap­ta­tion, are all sep­a­rate things. If you built a toaster, you wouldn’t ex­pect the toaster to re­shape it­self when you tried to cram in a whole loaf of bread; yes, you in­tended it to make toast, but that in­ten­tion is a fact about you, not a fact about the toaster. The toaster has no sense of its own pur­pose.

But a toaster is not an in­ten­tion-bear­ing ob­ject. It is not a mind at all, so we are not tempted to at­tribute goals to it. If we see the toaster as pur­posed, we don’t think the toaster knows it, be­cause we don’t think the toaster knows any­thing.

It’s like the old test of be­ing asked to say the color of the let­ters in “blue”. It takes longer for sub­jects to name this color, be­cause of the need to un­tan­gle the mean­ing of the let­ters and the color of the let­ters. You wouldn’t have similar trou­ble nam­ing the color of the let­ters in “wind”.

But a hu­man brain, in ad­di­tion to be­ing an ar­ti­fact his­tor­i­cally pro­duced by evolu­tion, is also a mind ca­pa­ble of bear­ing its own in­ten­tions, pur­poses, de­sires, goals, and plans. Both a bee and a hu­man are de­signs, but only a hu­man is a de­signer. The bee is “wind”, the hu­man is “blue”.

Cog­ni­tive causes are on­tolog­i­cally dis­tinct from evolu­tion­ary causes. They are made out of a differ­ent kind of stuff. Cog­ni­tive causes are made of neu­rons. Evolu­tion­ary causes are made of an­ces­tors.

The most ob­vi­ous kind of cog­ni­tive cause is de­liber­ate, like an in­ten­tion to go to the su­per­mar­ket, or a plan for toast­ing toast. But an emo­tion also ex­ists phys­i­cally in the brain, as a train of neu­ral im­pulses or a cloud of spread­ing hor­mones. Like­wise an in­stinct, or a flash of vi­su­al­iza­tion, or a fleet­ingly sup­pressed thought; if you could scan the brain in three di­men­sions and you un­der­stood the code, you would be able to see them.

Even sub­con­scious cog­ni­tions ex­ist phys­i­cally in the brain. “Power tends to cor­rupt,” ob­served Lord Ac­ton. Stalin may or may not have be­lieved him­self an al­tru­ist, work­ing to­ward the great­est good for the great­est num­ber. But it seems likely that, some­where in Stalin’s brain, there were neu­ral cir­cuits that re­in­forced plea­surably the ex­er­cise of power, and neu­ral cir­cuits that de­tected an­ti­ci­pa­tions of in­creases and de­creases in power. If there were noth­ing in Stalin’s brain that cor­re­lated to power—no lit­tle light that went on for poli­ti­cal com­mand, and off for poli­ti­cal weak­ness—then how could Stalin’s brain have known to be cor­rupted by power?

Evolu­tion­ary se­lec­tion pres­sures are on­tolog­i­cally dis­tinct from the biolog­i­cal ar­ti­facts they cre­ate. The evolu­tion­ary cause of a bird’s wings is mil­lions of an­ces­tor-birds who re­pro­duced more of­ten than other an­ces­tor-birds, with statis­ti­cal reg­u­lar­ity ow­ing to their pos­ses­sion of in­cre­men­tally im­proved wings com­pared to their com­peti­tors. We com­press this gar­gan­tuan his­tor­i­cal-statis­ti­cal macro­fact by say­ing “evolu­tion did it”.

Nat­u­ral se­lec­tion is on­tolog­i­cally dis­tinct from crea­tures; evolu­tion is not a lit­tle furry thing lurk­ing in an undis­cov­ered for­est. Evolu­tion is a causal, statis­ti­cal reg­u­lar­ity in the re­pro­duc­tive his­tory of an­ces­tors.

And this logic ap­plies also to the brain. Evolu­tion has made wings that flap, but do not un­der­stand flap­piness. It has made legs that walk, but do not un­der­stand walky­ness. Evolu­tion has carved bones of cal­cium ions, but the bones them­selves have no ex­plicit con­cept of strength, let alone in­clu­sive ge­netic fit­ness. And evolu­tion de­signed brains them­selves ca­pa­ble of de­sign­ing; yet these brains had no more con­cept of evolu­tion than a bird has of aero­dy­nam­ics. Un­til the 20th cen­tury, not a sin­gle hu­man brain ex­plic­itly rep­re­sented the com­plex ab­stract con­cept of in­clu­sive ge­netic fit­ness.

When we’re told that “The evolu­tion­ary pur­pose of anger is to in­crease in­clu­sive ge­netic fit­ness,” there’s a ten­dency to slide to “The pur­pose of anger is re­pro­duc­tion” to “The cog­ni­tive pur­pose of anger is re­pro­duc­tion.” No! The statis­ti­cal reg­u­lar­ity of an­ces­tral his­tory isn’t in the brain, even sub­con­sciously, any more than the de­signer’s in­ten­tions of toast are in a toaster!

Think­ing that your built-in anger-cir­cuitry em­bod­ies an ex­plicit de­sire to re­pro­duce, is like think­ing your hand is an em­bod­ied men­tal de­sire to pick things up.

Your hand is not wholly cut off from your men­tal de­sires. In par­tic­u­lar cir­cum­stances, you can con­trol the flex­ing of your fingers by an act of will. If you bend down and pick up a penny, then this may rep­re­sent an act of will; but it is not an act of will that made your hand grow in the first place.

One must dis­t­in­guish a one-time event of par­tic­u­lar anger (anger-1, anger-2, anger-3) from the un­der­ly­ing neu­ral cir­cuitry for anger. An anger-event is a cog­ni­tive cause, and an anger-event may have cog­ni­tive causes, but you didn’t will the anger-cir­cuitry to be wired into the brain.

So you have to dis­t­in­guish the event of anger, from the cir­cuitry of anger, from the gene com­plex which laid down the neu­ral tem­plate, from the an­ces­tral macro­fact which ex­plains the gene com­plex’s pres­ence.

If there were ever a dis­ci­pline that gen­uinely de­manded X-Treme Nit­pick­ing, it is evolu­tion­ary psy­chol­ogy.

Con­sider, O my read­ers, this sor­did and joyful tale: A man and a woman meet in a bar. The man is at­tracted to her clear com­plex­ion and firm breasts, which would have been fer­til­ity cues in the an­ces­tral en­vi­ron­ment, but which in this case re­sult from makeup and a bra. This does not bother the man; he just likes the way she looks. His clear-com­plex­ion-de­tect­ing neu­ral cir­cuitry does not know that its pur­pose is to de­tect fer­til­ity, any more than the atoms in his hand con­tain tiny lit­tle XML tags read­ing “<pur­pose>pick things up</​pur­pose>”. The woman is at­tracted to his con­fi­dent smile and firm man­ner, cues to high sta­tus, which in the an­ces­tral en­vi­ron­ment would have sig­nified the abil­ity to provide re­sources for chil­dren. She plans to use birth con­trol, but her con­fi­dent-smile-de­tec­tors don’t know this any more than a toaster knows its de­signer in­tended it to make toast. She’s not con­cerned philo­soph­i­cally with the mean­ing of this re­bel­lion, be­cause her brain is a cre­ation­ist and de­nies ve­he­mently that evolu­tion ex­ists. He’s not con­cerned philo­soph­i­cally with the mean­ing of this re­bel­lion, be­cause he just wants to get laid. They go to a ho­tel, and un­dress. He puts on a con­dom, be­cause he doesn’t want kids, just the dopamine-no­ra­drenal­ine rush of sex, which re­li­ably pro­duced offspring 50,000 years ago when it was an in­var­i­ant fea­ture of the an­ces­tral en­vi­ron­ment that con­doms did not ex­ist. They have sex, and shower, and go their sep­a­rate ways. The main ob­jec­tive con­se­quence is to keep the bar and the ho­tel and con­dom-man­u­fac­turer in busi­ness; which was not the cog­ni­tive pur­pose in their minds, and has vir­tu­ally noth­ing to do with the key statis­ti­cal reg­u­lar­i­ties of re­pro­duc­tion 50,000 years ago which ex­plain how they got the genes that built their brains that ex­e­cuted all this be­hav­ior.

To rea­son cor­rectly about evolu­tion­ary psy­chol­ogy you must si­mul­ta­neously con­sider many com­pli­cated ab­stract facts that are strongly re­lated yet im­por­tantly dis­tinct, with­out a sin­gle mixup or con­fla­tion.