Individual differences in hormonal responsiveness to social encounters: Commentary on Félix et al., 2020 and review of pertinent issues

The results of a recent study, Félix et al., 2020, give new information about the behavioral and endocrine correlates of individual differences in the potential for androgen response in male cichlid fish. We think the study raises issues that are pertinent to the study of hormones and competition in other species, particularly humans. Focusing mostly on androgen reactivity to social challenge, we emphasize the importance of inter-individual variability in physiology, personality, and motivation in studies of hormone responses to social encounters. Additionally, we give special attention to matters of “repeatability” and the timing of hormone sampling. We conclude with an appreciation of the value of comparative analysis in behavioral endocrinology.