Monkey Business?

Serotonin is involved in many behaviours, and new research suggests that a mutation in a gene that transports the brain chemical serotonin could influence our social behaviour.

This is based on American research using rhesus macaque monkeys because they are the only other primates with a particular genetic trait. Usually we are homozygous for this  emotion-regulating serotonin transporter gene, having either two long (L/L) or two short (S/S) versions. But previous research has shown that there are a few people – more common in those of Asian descent – who are heterozygous and have social anxiety and similar behaviours. Rhesus macaque monkeys are the only other primates with this genetic trait. The research showed that those with the S/L version spent less time looking directly at the faces and eyes of other monkeys, and were less likely to want to look at a picture of a high-status male monkey, and also were less likely to be risk takers, than those who were homozygous.

Platt says, “For both human and non-human primates, faces and eyes are a rich source of social information, and it’s well-established that both humans and macaques tend to direct visual attention to faces, especially the eye region. Rhesus monkeys live in highly despotic societies and convey social rank information by making threats and showing dominant and submissive behaviors.”

The findings could give researchers a new model to help in studying social anxiety, and perhaps more serious disorders such as autism and schizophrenia.

According to Watson, “Altogether, our data show that genetic variation in serotonin function does contribute to social reward and punishment in macaques, and thus shapes social behavior in both humans and rhesus macaques. This study confirms rhesus monkeys can serve as a model of what goes on in our brains, even in the case of social behavior.”

How similar are we to primates such as rhesus monkeys?

What are the arguments fordoing psychological research on animals such as these, and what are the arguments against this?