The dual-hormone hypothesis
High testosterone is not a leadership stack. It is a term in an interaction, and the other term is cortisol.
Folk claim
High testosterone makes leaders. Optimize T and you optimize status.
What the papers say
Mehta and Josephs (2010) found T related to dominant, leader-like behavior only when cortisol was low. When cortisol was high, the relationship vanished or reversed. Mehta and Prasad (2015) and Carré and Olmstead (2015) refined the claim around contest-induced T change. Later quantitative reviews find a small, messy effect. The folk line is a dropped interaction term.
If you insist on an endocrine story of rank, tell the two-hormone story, cite the small effect, and remember that lab leadership is not a P&L.
The paper that should have killed the slogan
Mehta and Josephs ran leadership and competition protocols and plotted T against behavior at high vs low cortisol. The simple slope that Instagram wanted existed on one side of the split only. On the other side it died. That is an interaction, and interactions are easy to hide in a thread.
What exogenous T actually did to bargaining
The brief mentioned 'Camerer et al.' and the ultimatum game. The Nature experiment is Eisenegger et al. (2010): T made women more fair as proposers; the belief that one received T made them less fair. Zak (2009) found less male generosity. Cueva et al. (2017) found a null on male rejections. This atlas keeps all three on the same edge. A contested RCT is still more informative than a confident blog.
The loop people skip
Mazur and Booth's winner–loser model is a feedback loop: the contest moves T, T colors the next contest. Treating T as a fixed 'level you optimize' misses the dynamics. Sleep restriction (Leproult 2011; Spiegel 1999) is a cleaner experimental handle on the same system than a supplement stack.
Edges in this case
Observational · Contested
Testosterone→Status seeking
Basal T is not a leadership switch. The dual-hormone claim is an interaction, and the interaction is small and contested.
Observational · Moderate
Cortisol→Leadership effectiveness
High cortisol is the condition under which 'high T = leader' fails. The internet quote drops this term.
Longitudinal / panel · Moderate
Contest outcome (win / loss)→Testosterone
Winning a meaningful contest raises T relative to losing. That T change then colors the next contest. A loop, not an arrow.
Randomized trial · Contested
Testosterone→Ultimatum rejection
Exogenous T changes bargaining — but not in the folk direction, and not in every lab.
Sources
- P. H. Mehta et al. (2010). Testosterone and cortisol jointly regulate dominance: Evidence for a dual-hormone hypothesis
- P. H. Mehta et al. (2015). The dual-hormone hypothesis: a brief review and future research agenda
- J. M. Carré et al. (2015). Social neuroendocrinology of human aggression: Examining the role of competition-induced testosterone dynamics
- C. Eisenegger et al. (2010). Prejudice and truth about the effect of testosterone on human bargaining behaviour
- S. N. Geniole et al. (2020). Evidence from meta-analyses of the facial width-to-height ratio versus the dual-hormone hypothesis as predictors of status-seeking
Cite this page
What Causes What. “The dual-hormone hypothesis.” https://whatcauseswhat.org/cases/dual-hormone (atlas updated 2026-08-31).