Social behavior, cortisol, and sIgA levels in preschool children.

OBJECTIVE: This study aims to explore the possible existence of behavioral states in early stages of development, which are associated with specific cortisol production profiles and consequently with changes in the immune response [secreted immunoglobulin A (sIgA)]. METHODS: The subjects were 27 boys and 21 girls of preschool age whose behavior was videotaped in free play interactions. Their behavior was then evaluated using an ethogram of the social behavior of the child. Cortisol levels were measured using a radioimmunoassay in saliva samples, and sIgA levels were measured by means of an ELISA, also in saliva samples. RESULTS: No correlation between cortisol and sIgA levels was found. Variance analysis revealed that the only behavioral pattern, which showed significant differences with regard to cortisol levels, was isolation. CONCLUSIONS: There seems to be a connection between cortisol levels and isolation behavior; we found no relation between high cortisol levels and a lower sIgA secretion.

Relating testosterone levels and free play social behavior in male and female preschool children.

This study assessed potential relationships between a series of behavioral measures seen in the interactions of preschool children with their peers (particularly aggressive behavior) and testosterone levels. 28 boys and 20 girls of preschool age were videotaped in free play interactions. Their behavior was then evaluated with particular emphasis on aggression and affiliation in play and social interactions. Testosterone levels were measured using radioimmunoassay in saliva samples. Correlation analysis revealed a positive relationship in boys between testosterone and giving and receiving aggression in the context of 'social interactions' (serious aggression), but not in the context of play (playful aggresstion). Testosterone can be a useful biological marker for serious aggression (and behavioral patterns reflecting different levels of sociability) in preschool boys.