Between- and within-sex variation in hormonal responses to psychological stress in a large sample of college students

Abstract

This study investigated (1) sex differences in hormonal responses to psychosocial stress; (2) the relation between variability in pre-test hormone concentrations and stress-induced hormonal changes; and (3) some possible sources of within-sex variation in pre-test hormone concentrations and in hormonal responses to the test in a large human subject population. To this end, changes in salivary concentrations of testosterone and cortisol in response to a mild psychosocial stressor (a set of computerized economic decision-making tests) were measured in a sample of over 500 MBA students. Males had higher concentrations of testosterone and cortisol than females both before and after the test. After taking effects of time of testing on hormone concentrations into account, testosterone showed a post-test decrease in males but not in females. Cortisol level increased in both sexes but the post-test increase was larger in females than in males. At the individual level, the pre-test concentrations of testosterone and cortisol predicted both the direction and the magnitude of the post-test hormone change, so that low pre-test hormone concentrations showed large post-test increases whereas high pre-test concentrations showed large post-test decreases. Within-sex variation in hormone concentrations was not accounted for by variation in 2D:4D digit length ratio, a marker of prenatal androgen exposure, but by social variables. Single males without a stable romantic partner had higher testosterone level than males with stable partners, and both males and females without a partner showed a greater cortisol response to the test than married individuals with or without children. Studies conducted with large sample sizes such as this one can help understand normative patterns of hormonal responses to psychosocial stimuli as well as identify the sources of interindividual variation in endocrine function.

Keywords::

• Decision-making stress
• digit length ratio
• salivary cortisol
• salivary testosterone
• sex differences
• stable partnership

Acknowledgements

This study is part of a larger project funded by the Templeton Foundation and the Zell Center; without their support none of this would have been possible. In addition, Luigi Zingales thanks the CRSP center and the Global Financial Market Initiative at the University of Chicago for financial support. We thank Ernesto Reuben for his excellent research assistantship during the project and Moshe Hoffman and Paul Rogerson for their help in hand scanning. We also thank Sari Van Anders for her helpful comments on the manuscript.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.