Said Platt, "So, now we have an excellent model of how temperament or status can modulate the strength of these two seemingly independent attention systems -- cognitive and reflexive -- in the brain. We can begin to trace the neural pathways by which social information feeds into the structures that control the eyes. And, we can explore whether such influences as hormonal levels, particularly testosterone, influence ranking. For example, we can manipulate testosterone levels, or give anxiety-reducing drugs, to determine an effect on social status, using gaze-following as a measure."
The neurobiologists' basic studies could also have application to understanding the origins of autism, said Platt. One theory, for example, holds that high levels of testosterone in utero cause "hypermasculinization" of the brain, which suppresses the reflexive ability to orient socially -- a characteristic of autism, he noted. Also, he said, such studies could aid understanding a wide range of disorders such as social anxiety.
More broadly, said Shepherd, such studies in monkeys will enable greater insight into the basic machinery of social interaction.
"Thanks to a combination of molecular and behavioral studies, we're starting to be able to investigate the neural machinery that allows humans to empathize, to form strong social bonds, to do things like share food and to cooperate," he said. "Besides suggesting ways of diagnosing or assisting people with autism and other disorders, such studies are also a means of understanding what enables us to be social."