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Lies And Deception Led To Human Intelligence

May 7, 2010

I never would’ve guessed this, but to a large extent our intelligence evolved as a means to deceive others within our social groups.  When studying anthropology today I came across this:

The prevailing view among scientists today is that the brain size increase that occurred in great apes and was extended into hominids resulted from the premium that natural selection placed on individuals that were socially clever. This theory, often called social intelligence or Machiavellian intelligence, argues that the primary evolutionary benefit of large brain size was that it allowed apes and hominids to cope with and even exploit increasingly complex social relations.  In large social groups, each individual must remember the network of alliances, rivalries, debts, and credits that exist among group members.  This is not so different from the politics of our own day-to-day lives.  Frans de Waal (1982) has observed that chimpanzees seem to engage in a “service economy” in which they barter alliances and other forms of support with one another.

The individuals best able to exploit this web of social relationships would have reaped more mating success than their group mates. Richard Byrne and Andrew Whiten(1988a, b) point out that the ability to subtly manipulate others is a fundamental aspect of group life.  Robin Dunbar (1992) argues that as average group size increased, the cerebrum, or neocortex, of the primate brain increased in size to handle the additional input of social information, in much the same way that a switchbaord would be enlarged to handle added telephone traffic.  This effect holds true even when we take into account the evolved patterns of social grouping.  Dunbar observes that small-brained primates, such as strepsirhines, typically live alone or in smaller groups than do most monkeys and apes.

Richard Byrne and Andrew Whiten (1988b) collected examples of potential lying in nonhuman primates and concluded that this behavior showed and evolutionary trend, one that was more widespread in higher primates.  Great apes seem to be skilled at deceiving one another, whereas lemurs rarely if ever engage in tactical deception.  Cheney and Seyfarth found that vervet monkeys engage in tactical deception, or lying.  In Cheney and Seyfarth’s study, a vervet gave a predator alarm call as the group fed in a desired fruit tree.  As other group members fled from the “predator,” the call-giver capitalized on its lie by feeding aggressively in their absence.  Great apes are characterized by their clever use of deception to get what they want.  Craig Stanford once watched a low-ranking Gombe male chimpanzee named Beethoven mate with a female, despite the presence of the alpha male Wilkie, by using tactical deception.  As a party of chimpanzees sat in a forest clearing, Beethoven did a charging display through the middle of the group.  Because Beethoven was a low-ranking male, this was taken by the alpha Wilkie as an act of insubordination.  As Beethoven charged past Wilkie and into dense thickets, Wilkie pursued and launched into his own display.  With Wilkie absorbed in his display of dominance, Beethoven furtively made his way back to the clearing and mated with an eagerly awaiting female.

Why do primate researchers think that deception is at the heart of understanding the roots of human cognition?  The reason lies in the nature of intentional deception.  In order to lie to someone, you must possess a theory of mind.  That is, you must be able to place yourself in the mind of another, to understand the other’s mental states.  The ability to lie, to imitate, and to teach all rely on the assumption that the object of your actions thinks as you do. Whether nonhuman primates possess a human-like theory of mind is a subject of intense debate.  Small children develop a theory of mind as they grow up, but not until they are past the age of about 2 years.  Of course, to some extent the ability to impute mental states to others around you is a fundamental prerequisite to living in a complex social group.  Among primates social dynamics are complex enough that a theory of mind becomes a critical issue.

It seems lying and deception go way back.  It’s nothing new.  Our intelligence itself has evolved because we could skillfully lie and exploit the others around us.  But looking on the bright side, if alpha males are hording all the food and females, you have to resort to deception and cleverness in order to survive.   I say good for Beethoven.

If this is a core process of evolution we should probably be wary of aliens as they’re just as likely to be liars as we are.

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