Jan 23 2009
The Nature of Personality
Twin studies and longitudinal research suggest that personality attributes are strongly influenced by an individual’s genetic make-up. Among groups of just about any type of animal, including birds, you will find individuals that are more risk-averse (inhibited/shy), others less.
Recent research on macaques illustrates how genes can influence personality.
A genetic variation involving the brain chemical serotonin has been found to shape the social behavior of rhesus macaque monkeys, which could provide researchers with a new model for studying autism, social anxiety and schizophrenia. Humans and macaques are the only members of the primate family to have this particular genetic trait.
Here’s the science part. The strength of a study, of course, is in the details.
Platt’s research group at Duke studied behavior and social anxiety in two groups of monkeys with variations in the serotonin transporter gene, crucial to regulating emotion. Based on earlier observations in humans, the scientists knew that humans carry two versions of the gene, long and short. Some people have two long versions (L/L), but the people with one of each (S/L) are known to experience a higher incidence of social anxiety and other behaviors.
And the kicker -
In a series of experiments, the S version of the gene in monkeys was found to influence their risk-taking when faced with particular social stimuli.
In a sense, serotonin is the testosterone of neurotransmitters. Of the hormones, testosterone gets all the talk, particularly the pseudo-scientific speculation. The study of neurotransmitters is even “younger” than that of hormones. And serotonin has been getting a lion’s share of the attention. However, as with testosterone, there is likely a good reason for that. While their importance, and the immediacy of their influences, can be overstated, they are hugely important, naturally-occuring chemicals. And millions of people now take level-boosting drugs.
