Developmental and personality correlates of adrenocortical activity as indexed by salivary cortisol: observations in the age range of 35 to 65 years.

Unstimulated salivary cortisol concentrations were measured in 767 adults aged 35-65 yr over the course of one day. Interindividual differences in early morning cortisol concentrations showed consistent and significant relationships with demographic and psychological variables. Socioeconomic status was positively associated with cortisol levels. Relationships of cortisol levels with age were moderated by gender: for women, a negative regression of cortisol level on age was observed while no significant age effects were obtained for men. In bivariate and multivariate regression analyses, a positive association between cortisol levels and indicators of successful development and personal well-being was observed; these relationships were more pronounced for the male sample. Intradyadic correlations further revealed a slight but significant association of morning cortisol levels within married couples. The findings are discussed with respect to mediating developmental mechanisms and pathophysiological implications.