Tag Archives: evolutionary-psychology

The Minds of Dogs and How Pointing Evolved

Recent research sug­gests that domest­ic dogs seem cap­able of dis­play­ing a rudi­ment­ary “the­ory of mind” — a very human char­ac­ter­ist­ic whereby you are able to attrib­ute men­tal states to oth­ers that do not neces­sar­ily coin­cide with your own (in a nut­shell). Stray domest­ic dogs, mean­while, do not dis­play this trait, sug­gest­ing that such men­tal attrib­utes are developed through close con­tact with humans. That’s inter­est­ing, but not the main reas­on I’m shar­ing this inform­a­tion with you.

This cog­nit­ive dif­fer­ence between stray domest­ic dogs and their house­bound brethren was uncovered by test­ing wheth­er or not they under­stood the very human action of point­ing (y’know, with your index fin­ger). What struck me most in this dis­cus­sion was this brief the­ory of how the action of point­ing evolved:

Go ahead, let your wrist go limp and look at your hand from the side, or if you’re too insec­ure in your own sexu­al­ity, just pic­ture Adam’s limp wrist at the moment of cre­ation in Michelan­gelo’s mas­ter­piece on the Sis­tine Chapel’s ceil­ing. See how even in this relaxed state the index fin­ger is slightly exten­ded? By con­trast, when chimps do this […] their index fin­ger falls nat­ur­ally in line with their oth­er fin­gers. Pov­inelli and Dav­is reas­on that this subtle evol­u­tion­ary change in the mor­pho­logy of our hands, which occurred after humans and chim­pan­zees last shared a com­mon ancest­or five mil­lion to sev­en mil­lion years ago, is at least par­tially respons­ible for the fact that human point­ing with the index fin­ger is so cul­tur­ally ubi­quit­ous today.

The argu­ment goes some­thing like this. When young infants begin reach­ing for objects just out of their range, adults are most likely to respond to those reach­ing attempts and to retrieve the item for the baby when the lat­ter­’s index fin­ger is more prom­in­ently exten­ded. That is to say, ini­tially, the adult mis­takenly reads into the child’s reach­ing attempt as a com­mu­nic­at­ive ges­ture on the part of the child. Over time, this dynam­ic between the child and adult serves to fur­ther “pull out” the index fin­ger because the child impli­citly learns the beha­vi­or­al asso­ci­ation, so that it slowly becomes a genu­ine point­ing ges­ture.

An Evolutionary Hierarchy of Needs

Parts of Abra­ham Maslow’s fam­ous 1940s hier­archy of needs are out­dated and thought of as quaint by the sci­entif­ic com­munity, accord­ing to a team who have revised the hier­archy to take into con­sid­er­a­tion sci­entif­ic find­ings from the last 60+ years.

Maslow’s pyr­am­id is used to rep­res­ent the hier­archy of basic human motiv­a­tions, from basic phys­ic­al needs up to self-actu­al­isa­tion. Now, address­ing many of the cri­ti­cisms of the ori­gin­al, the updated hier­archy of needs (which isn’t really a hier­archy at all) places evol­u­tion­ary motiv­a­tions toward the top:

The revamp of Maslow’s pyr­am­id reflects new find­ings and the­ory from fields like neur­os­cience, devel­op­ment­al psy­cho­logy and evol­u­tion­ary psy­cho­logy […]

The research team […] restruc­tured the fam­ous pyr­am­id after observing how psy­cho­lo­gic­al pro­cesses rad­ic­ally change in response to evol­u­tion­ar­ily fun­da­ment­al motives, such as self-pro­tec­tion, mat­ing or status con­cerns.

The bot­tom four levels of the new pyr­am­id are highly com­pat­ible with Maslow’s, but big changes are at the top. Per­haps the most con­tro­ver­sial modi­fic­a­tion is that self-actu­al­iz­a­tion no longer appears on the pyr­am­id at all. At the top of the new pyr­am­id are three evol­u­tion­ar­ily crit­ic­al motives that Maslow over­looked – mate acquis­i­tion, mate reten­tion and par­ent­ing.

The research­ers state in the art­icle that while self-actu­al­iz­a­tion is inter­est­ing and import­ant, it isn’t an evol­u­tion­ar­ily fun­da­ment­al need. Instead, many of the activ­it­ies that Maslow labeled as self-actu­al­iz­ing (artist­ic cre­ativ­ity, for example) reflect more bio­lo­gic­ally basic drives to gain status, which in turn serves the goal of attract­ing mates. […]

For humans repro­duc­tion is not just about sex and pro­du­cing chil­dren. It’s also about rais­ing those chil­dren to the age at which they can repro­duce as well. Con­sequently, par­ent­ing sits atop the revamped pyr­am­id.

There are oth­er dis­tinc­tions as well. For Maslow, once a need was met, it dis­ap­peared as the indi­vidu­al moved on to the next level. In the reworked pyr­am­id, needs over­lap one anoth­er and coex­ist, instead of com­pletely repla­cing each oth­er. For example, cer­tain envir­on­ment­al cues can make them come back. If you are walk­ing down the street think­ing about love, art or the mean­ing of life, you will revert quickly to the self-pro­tec­tion level if you see an omin­ous-look­ing gang of young men headed your way.

via @sandygautam

Evolutionary Theory of Fiction

The age of “polit­ic­ally charged” ana­lyses of lit­er­at­ure has passed and the latest phase is that of ana­lys­ing fic­tion through the lens of evol­u­tion­ary psy­cho­logy, look­ing at how the brain pro­cesses lit­er­at­ure.

Humans can com­fort­ably keep track of three dif­fer­ent men­tal states at a time, Ms. Zun­shine said. For example, the pro­pos­i­tion “Peter said that Paul believed that Mary liked chocol­ate” is not too hard to fol­low. Add a fourth level, though, and it’s sud­denly more dif­fi­cult. And exper­i­ments have shown that at the fifth level under­stand­ing drops off by 60 per­cent, Ms. Zun­shine said. Mod­ern­ist authors like Vir­gin­ia Woolf are espe­cially chal­len­ging because she asks read­ers to keep up with six dif­fer­ent men­tal states, or what the schol­ars call levels of inten­tion­al­ity.

It’s a short art­icle, and left me want­ing more. More will no doubt come when this field matures.

via Arts and Let­ters Daily

Reasons for Compassion and Charity

Tack­ling the idea that human empathy is self-serving, Dacher Kelt­ner, for UC Berke­ley’s Great­er Good magazine, reviews a num­ber of stud­ies look­ing at why we are com­pas­sion­ate.

In oth­er research by Emory Uni­ver­sity neur­os­cient­ists James Rilling and Gregory Berns, par­ti­cipants were giv­en the chance to help someone else while their brain activ­ity was recor­ded. Help­ing oth­ers triggered activ­ity in […] por­tions of the brain that turn on when people receive rewards or exper­i­ence pleas­ure. This is a rather remark­able find­ing: help­ing oth­ers brings the same pleas­ure we get from the grat­i­fic­a­tion of per­son­al desire.

The brain, then, seems wired up to respond to oth­ers’ suffering—indeed, it makes us feel good when we can alle­vi­ate that suf­fer­ing. But do oth­er parts of the body also sug­gest a bio­lo­gic­al basis for com­pas­sion?

That’s the bio­lo­gic­al view on com­pas­sion, but what about oth­er views? Ryan Sager looks at altru­ism from an evol­u­tion­ary psy­cho­logy stand­point.

Stud­ies seem to indic­ate that per­ceived altru­ism enhances attract­ive­ness. [One study] for instance, finds that “coöperative beha­vi­or increases the per­ceived attract­ive­ness of the cooper­at­or.” (The same study also finds that people are more altru­ist­ic toward people who are attract­ive — but you prob­ably already knew that.) Like­wise, [a] paper in the Brit­ish Journ­al of Psy­cho­logy finds evid­ence that women have a sig­ni­fic­ant pref­er­ence for altru­ist­ic mates, more so than men.

via Arts and Let­ters Daily

What Makes Us Human: Tolerance and Coöperation

In the 1950s, Rus­si­an sci­ent­ist Dmitri Bely­aev ran a select­ive breed­ing pro­ject to, by arti­fi­cial selec­tion, breed (incred­ibly cute) domest­ic­ated sil­ver foxes. The res­ults of this multi-dec­ade exper­i­ment were impress­ive, espe­cially giv­en that the foxes were selec­ted solely for their amic­ab­il­ity toward humans:

After only forty gen­er­a­tions, the selec­ted foxes began to dis­play changes you (and Dar­win, too) might think would take mil­lions of years to evolve. As expec­ted, they became incred­ibly friendly toward humans. Whenev­er they saw people, they barked, wagged their tails, sniffed the people, and licked their faces. But even stranger were the phys­ic­al changes, which occurred at a high­er fre­quency than in the con­trol group. The ears of the selec­ted foxes became floppy. Their tails turned curly. Their coats lost their cam­ou­flage and became spotty, with a star pat­tern appear­ing on the fore­head. Their skulls became smal­ler. In short, they looked and behaved remark­ably like their close rel­at­ive the domest­ic dog.

The above quote comes from an art­icle by Vanessa Woods and Bri­an Hare on Edge that looks at why our ancest­ors ‘came down from the trees’ and what sep­ar­ates us from oth­er hom­in­ids, spe­cific­ally chim­pan­zees (hint: it’s not the the­ory of mind, but tol­er­ance and coöperation).

So what we have are chimps who coöperate but aren’t very tol­er­ant, and bonobos who are very tol­er­ant but don’t really coöperate in the wild. What prob­ably happened six mil­lion years ago, when hom­in­ids split from the ancest­or we share with chim­pan­zees and bonobos, is that we became very tol­er­ant, and this allowed us to coöperate in entirely new ways. Without this heightened tol­er­ance, we would not be the spe­cies we are today.