Salivary alpha-amylase and cortisol in toddlers: differential relations to affective behavior.

This study applies a minimally invasive and multi-system measurement approach (using salivary analytes) to examine associations between the psychobiology of the stress response and affective behavior in toddlers. Eighty-seven 2-year-olds (48 females) participated in laboratory tasks designed to elicit emotions and behavior ranging from pleasure/approach to fear/withdrawal. Saliva samples were collected pretask and immediately posttask, and assayed for markers of sympathetic nervous system (alpha-amylase or sAA) and hypothalamic-pituitary-adrenal axis (cortisol) activity.