Sex differences in biological response to peer rejection and performance challenge across development: A pilot study

A pilot study of sex differences in biological response to peer rejection and performance challenges across development was conducted. Participants were 59 typically-developing children (ages 8-17; 58% girls); 59 children completed one challenge: 37 completed both challenges. Following a habituation session, participants completed peer rejection (exclusion challenges) and/or performance (speech, arithmetic, tracing) stress sessions. Saliva cortisol and alpha amylase (AA) were measured throughout. Post-pubertal girls showed increased AA and equivalent cortisol output in response to rejection vs. performance; pre-pubertal girls showed heightened cortisol and AA response to performance vs. rejection. Boys showed similar biological responses across puberty, with pre- and post-pubertal boys demonstrating heightened cortisol, but equivalent AA output in response to performance vs. rejection stressors. Although results are preliminary, they suggest increases in relative sensitivity to rejection vs. performance stressors and malleability of stress response across development in girls, but stability of stress response across development in boys. Future, larger-scale, longitudinal studies are needed.