The judgments we make about the intimacy of other couples' relationships appear to be influenced by the brain chemical serotonin, reports a new study published in Biological Psychiatry. Healthy adult volunteers, whose levels of serotonin activity had been lowered, rated couples in photos as being less intimate and less romantic than volunteers with normal serotonin activity. The approach involved giving amino acid drinks to two groups of volunteers in order to manipulate blood concentrations of the amino acid tryptophan, which is a vital ingredient in the synthesis of serotonin. One group received drinks that contained tryptophan. The other group received drinks that did not contain tryptophan. They were then asked to make judgments about sets of photographs of couples. Differences in the judgments made by the two groups reflected changes in their serotonin activity.
"Serotonin is important in social behavior, and also plays a significant role in psychological disorders such as depression," explained Professor Robert Rogers of Oxford University, who led the research. "We wanted to see whether serotonin activity influences the judgments we make about peoples' close personal relationships." Read more>>>
