We propose to investigate the genetic basis of facial expressiveness in female rhesus macaques (Macaca mulatta). We will test the hypothesis that facial expressiveness is a genetically heritable trait by focusing on two main predictions. First, if individual differences in facial expressiveness are heritable, then closely related females will be more similar in expressiveness than distantly related females. Second, if facial expressiveness is influenced by genetics, then differences in genotype will be associated with individual differences in expressiveness. We will focus on two candidate genes associated with emotion regulation in humans, a length polymorphism within the promoter region (5-HTTLPR) of the serotonin transporter gene (SLC6A4), and a variable insertion in the gene encoding tryptophan hydroxylase (TPH2).This project will be carried out in collaboration with Lauren Brent and Michael Platt (Duke U.).
|An open mouth threat display from a female rhesus macaque|