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.