Bananas Made Me Arrogant

The New York Times' Sunday magazine has an interesting article about Williams syndrome, which is a genetic condition in which the ability to recognize space and basic math concepts is gone, but one is filled with a super high desire to interact with others. This is an interesting bit I'm copying at length, because it tries to explain why people feel uncomfortable around those who are really friendly but have obvious intelligence shortcomings....and also a look into how social demands drive brain development much more than tool usage.

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As an experiment of nature, Williams syndrome makes clear that while we are innately driven to connect with others, this affiliative drive alone will not win this connection. People with Williams rarely win full acceptance into groups other than their own. To bond with others we must show not just charm but sophisticated cognitive skills. But why? For vital relationships like those with spouses or business partners, the answer seems obvious: people want to know you can contribute. But why should casual friendships and group membership depend on smarts?

One possible answer a comes from the rich literature of nonhuman primate studies. For 40 years or so, primatologists like Jane Goodall, Frans de Waal and Robert Sapolsky have been studying social behavior in chimps, gorillas, macaques, bonobos and baboons. Over the past decade that work has led to a unifying theory that explains not only a huge range of behavior but also why our brains are so big and what their most essential work is. The theory, called the Machiavellian-intelligence or social-brain theory, holds that we rise from a lineage in which both individual and group success hinge on balancing the need to work with others with the need to hold our own — or better — amid the nested groups and subgroups we are part of.

It started with fruit. About 15 or 20 million years ago, the theory goes, certain forest monkeys in Africa and Asia developed the ability to digest unripe fruit. This left some of their forest-dwelling cousins — the ancestors of chimps, gorillas and humans — at a sharp disadvantage. Suddenly a lot of fruit was going missing before it ripened.

To find food, some of the newly hungry primate species moved to the forest edge. Their new habitat put more food in reach, but it also placed the primates within reach of big cats, canines and other savanna predators. This predation spurred two key evolutionary changes. The primates became bigger, giving individuals more of a fighting chance, and they started living in bigger groups, which provided more eyes to keep watch and a strength of numbers in defense.

But the bigger groups imposed a new brain load: the members had to be smart enough to balance their individual needs with those of the pack. This meant cooperating and exercising some individual restraint. It also required understanding the behavior of other group members striving not only for safety and food but also access to mates. And it called for comprehending and managing one’s place in an ever-shifting array of alliances that members formed in order not to be isolated within the bigger group.

How did primates form and manage these alliances? They groomed one another. Monkeys and great apes spend up to a fifth of their time grooming, mostly with regular partners in pairs and small groups. This quality time (grooming generates a pleasing release of endorphins and oxytocin) builds strong bonds. Experiments in which a recording of macaques screaming in alarm is played, for instance, have shown a macaque will respond much more strongly to a grooming partner’s cries than to cries from other members of the group. The large time investment involved seems to make a grooming relationship worth defending.

In this and other ways a group’s members would create, test and declare their alliances. But as the animals and groups grew, tracking and understanding all those relationships required more intelligence. According to the social-brain theory, it was this need to understand social dynamics — not the need to find food or navigate terrain — that spurred and rewarded the evolution of bigger and bigger primate brains.

This isn’t idle speculation; Robin Dunbar, an evolutionary psychologist and social-brain theorist, and others have documented correlations between brain size and social-group size in many primate species. The bigger an animal’s typical group size (20 or so for macaques, for instance, 50 or so for chimps), the larger the percentage of brain devoted to neocortex, the thin but critical outer layer that accounts for most of a primate’s cognitive abilities. In most mammals the neocortex accounts for 30 percent to 40 percent of brain volume. In the highly social primates it occupies about 50 percent to 65 percent. In humans, it’s 80 percent.

According to Dunbar, no such strong correlation exists between neocortex size and tasks like hunting, navigating or creating shelter. Understanding one another, it seems, is our greatest cognitive challenge. And the only way humans could handle groups of more than 50, Dunbar suggests, was to learn how to talk.

“The conventional view,” Dunbar notes in his book “Grooming, Gossip and the Evolution of Language,” “is that language evolved to enable males to do things like coordinate hunts more effectively. . . . I am suggesting that language evolved to allow us to gossip.”