Williams Syndrome

There’s a fascinating article by David Dobbs in this weekend’s NYT magazine about a genetic brain abnormality called Williams Syndrome (the link is under the del.icio.us heading over to the left on this page). Williams, as it is usually called, is manifested by low IQ (usually in the 60’s, or Mild Mental Retardation range), deficits in spacial functioning, and an amazing gregariousness. These folks really, really love to engage socially with others. They suffer, too, because others are not as ready to be friends with them, as they are to be friends (with anyone). They fail to detect many social cues, such as facial expressions indicating boredom or disinterest. The unique set of characteristics is making Williams Syndrome a sort of natural experimental condition that illuminates human social functioning. Here is an excerpt from the article:

People with Williams [are overly trusting, and generally unable to perceive deceptive behavior in others]. Generating and detecting deception and veiled meaning requires not just the recognition that people can be bad but a certain level of cognitive power that people with Williams typically lack. In particular it requires what psychologists call “theory of mind,” which is a clear concept of what another person is thinking and the recognition that the other person a) may see the world differently than you do and b) may actually be thinking something different from what he’s saying.

Cognitive scientists argue over whether people with Williams have theory of mind. Williams people pass some theory-of-mind tests and fail others. They get many jokes, for instance, but don’t understand irony. They make small talk but tend not to discuss the subtler dynamics of interpersonal relationships. Theory of mind is a slippery, multilayered concept, so the debate becomes arcane. But it’s clear that Williamses do not generally sniff out the sorts of hidden meanings and intentions that lie behind so much human behavior.

Andreas Meyer-Lindenberg, a psychiatrist and neurologist, spent the last several years at the National Institute of Mental Health exploring neural roots of mood, cognitive and behavioral disorders — including Williams syndrome.

“The most important abnormalities in Williams,” he says, “are circuits that have to do with basic regulation of emotions.”

A significant finding [in the brains of individuals with Williams] is [that there is] a dead connection between the orbitofrontal cortex, an area above the eye sockets and the amygdala, the brain’s fear center. The orbitofrontal cortex (or OFC) is associated with (among other things) prioritizing behavior in social contexts, and earlier studies found that damage to the OFC reduces inhibitions and makes it harder to detect faux pas. The Berman team detected a new contribution to social behavior: They found that while in most people the OFC communicated with the amygdala when viewing threatening faces, the OFC in people with Williams did not. This OFC-amygdala connection worked normally, however, when people with Williams viewed nonsocial threats, like pictures of snakes, sharks or car crashes.

This appears to explain the amygdala’s failure in Williams to fire at the sight of frightening faces and suggests a circuit responsible for Williamses’ lack of social caution. If the results hold up, the researchers will have cleanly defined a circuit evolved specifically to warn of threats from other people. This could account not just for the lack of social fear in Williams, but with it the wariness that can motivate deeper understanding. It is possible, in short, that people with Williams miss social subtleties not just because they lack cognitive tools but because they also lack a motivation — a fear of others — that the rest of us carry to every encounter. To Meyer-Lindenberg, the primacy of such circuits suggests that human sociability rises from evolutionarily reinforced mechanisms — a raw yearning to connect; fearfulness — that are so basic they’re easy to undervalue.

The disassociation of so many elements in Williams — the cognitive from the connective, social fear from nonsocial fear, the tension between the drive to affiliate and the drive to manipulate — highlights how vital these elements are and, in most of us, how delicately, critically entwined.