Steroid hormones and some evolutionary-relevant social interactions

The steroid hormones, testosterone and cortisol, have some common characteristics, but they are related to generally antagonic processes at both the physiological and psychological levels. In addition, they are the product of the activation of two axes, the hypothalamic–pituitary–gonadal (HPG) and hypothalamic–pituitary–adrenal (HPA), which are very sensitive to a wide range of stressors. Our review focuses on the role of testosterone and cortisol in some social situations, such as competition and others related to the challenge hypothesis, that are evolutionary-relevant and have a component of social stress. Research findings are presented on these points, especially emphasizing the relevance of how the individual interprets social stimuli and attributes of the other participant in the interaction, producing consequences in the response pattern to the social situation. This paper presents empirical support for the role of the interaction between the reproductive HPG and stress HPA axes in several social behaviors with important adaptive significance.