The lab is quiet until the faces appear. One after another, women’s portraits flash on the screen. A group of men rate them, decide whether they’d want to date them, then watch as someone treats each woman fairly or unfairly in a simple money-splitting game. Half the men have rubbed a hormone gel into their skin a few hours earlier. The difference it makes is not just about lust. It is about what feels just.
What this study actually found
New work in Psychoneuroendocrinology reports that an acute dose of testosterone changed how single heterosexual men saw and behaved toward women. Compared with placebo, testosterone led participants to rate women as more attractive and to express a stronger willingness to date them. It also made men more likely to punish people who treated women unfairly in an economic game, a behavior researchers call altruistic punishment. Notably, the women’s facial attractiveness already biased men’s responses, and testosterone appeared to amplify approach and protective motivations.
Testosterone increased men’s ratings of women’s attractiveness and their willingness to date, and it raised the frequency of altruistic punishment on women’s behalf (study summary).
The headline result that draws jokes online is the obvious one: hormones nudge desire. But the more interesting part is the moral coloration. The men did not just see more potential dates; they also became readier to intervene against unfairness directed at those potential dates, especially when the women were more attractive. That is a reminder that our sense of fairness is not sealed off from mating motives.
Two crucial caveats. First, this experiment shows causation for an acute increase in testosterone, not that men with naturally higher baseline testosterone are always more willing to date or punish unfairness. Second, the context matters. Decades of research suggest testosterone tunes status and approach motivation more than it simply stokes aggression. In some settings it can even encourage prosocial behavior to secure reputation and status. Reviews by Eisenegger and colleagues describe this “status-optimization” account of testosterone’s effects (overview). And the dual-hormone hypothesis holds that testosterone’s social effects often depend on cortisol levels and stress context (theory paper).
That nuance matters when interpreting findings like these. The economic game used here gives participants a chance to pay a small personal cost to punish someone who shortchanged a woman. On testosterone, men were more willing to incur that cost. Is that chivalry, virtue, or strategic signaling? In laboratory games, punishment can be sincere moral outrage, competitive dominance display, or both. The study’s design can detect the behavior, not its inner narrative.
Beauty, bias, and the mating mind
Another uncomfortable takeaway is how attractiveness shapes moral zeal. Before any hormone manipulation, men already punished unfairness against more attractive women more often. Testosterone did not erase that bias; it sat on top of it. This mirrors a broader “halo effect” in which physically attractive people receive better treatment across life domains, from hiring to leniency in courts. A hormone that heightens mating motivation could, inadvertently, magnify unequal attention and protection.
There is also a policy undercurrent. Testosterone replacement therapy has surged in the past decade, fueled by aging demographics, legitimate hypogonadism treatment, and splashy consumer marketing. Proposals to make testosterone easier to obtain crop up regularly. The new findings add a twist to that debate: widespread hormonal tinkering would not only change sex drive, it could reshape how men allocate moral concern in everyday interactions. That does not mean chaos, but it does argue for caution.
It is tempting to link all this to the so-called loneliness or dating crises among young people. But hormones are not destiny, and population trends are rarely explained by a single molecule. In fact, large time-use analyses show a long, pre-pandemic decline in in-person social engagement in the United States, especially among the young, driven by structural and technological shifts.
Average time spent with friends fell from 60 minutes/day in 2003 to 34 minutes/day in 2019, with further drops in 2020 (American Time Use Survey analysis).
Those trends point to work hours, urban design, digital substitution for in‑person time, and civic disconnection as major forces in the social landscape, rather than declining testosterone alone. Still, the study offers a window into how hormonal states might tilt behavior at the margins: whom we notice, how warmly we appraise them, and whether we step in on their behalf.
For readers wondering about generalizability, several obvious questions follow. Does testosterone similarly amplify attraction and protective punishment in gay men when judging male faces? Do women on exogenous testosterone show parallel shifts toward men’s faces, or does biology carve a different path? How long do these effects last beyond the acute dose used here? Answers will require larger, preregistered replications that compare endogenous levels and exogenous bumps, and that measure cortisol and personality to see who is most influenced.
- Mechanism: Do changes in attention and reward circuitry drive both the higher attractiveness ratings and the readiness to punish unfairness?
- Context: Do the effects persist outside the lab when reputational stakes are real and costly?
- Equity: Could testosterone amplify “pretty privilege,” leading to uneven protection or advocacy in workplaces and public spaces?
- Boundaries: How do cortisol, stress, and individual status motives gate these effects (dual-hormone model)?
It is also worth separating what the study did show from what it did not. It showed that a short-term rise in testosterone makes men more receptive to dating across the attractiveness spectrum, not just to the so-called “high attractiveness” group. That is important: the hormone appears to elevate general mating motivation rather than simply polishing the top of a desirability list.
The effect was broad-based: men on testosterone were more open to dating women in both “high” and “low” attractiveness groups, which points to a global change in receptivity rather than a narrow shift in taste.
Finally, a note on ethics and design. Sorting people into “high” and “low” attractiveness bins makes for clean statistics and messy feelings. The field should keep pressing for paradigms that measure social decision-making without unnecessarily demeaning participants. There are better ways to probe the mating mind.