Hormonal correlates of hand preference in free-ranging primates

In this research we examined hormonal correlates of hand preference in free -ranging primates. Specifically, we tested the hypothesis that levels oft h e stress hormone cortisol nod the male sex hormone testosterone are correla ted with handedness in male rhesus macaques (Macaca mulatta). We found sign ificant positive relationships between cortisol and testosterone levels sam pled during adolescnece ann the frequency of right- versus left-hand use sa mpled during adulthood. These data indicate that adolescent measures of cor tisol and testosterone are correlated with hemispheric specialization in ad ult free-ranging primates.