Human affection exchange: XII. Affectionate communication is associated with diurnal variation in salivary free cortisol

The present study tested the general hypothesis that, irrespective of the amount of affectionate communication one typically receives, the amount of affectionate communication one typically expresses to others is associated with the body's ability to handle stress. Twenty healthy young adults reported on their trait levels of expressed and received affection and then took four saliva samples over the course of a normal workday. The saliva samples were assayed for levels of free cortisol, an adrenal steroid hormone associated with physiological responses to stress. Controlling for received affection, expressed affection was strongly and positively associated with waking cortisol values and with aggregate values. It was also strongly and positively related to the magnitude of morning-to-evening decrease in cortisol levels, a rhythm indicative of an adaptive ability to handle stress. Theoretic and methodological implications are discussed.