High testosterone levels are linked with competitive, status-seeking social behaviors, whereas low testosterone is thought to encourage cooperative behaviors.

‘High-testosterone individuals appear to be more willing to harm others to achieve a desired outcome whereas low-testosterone individuals may experience greater empathy and are more interested in cooperating with others.’

"Evolutionary analysis suggests that natural selection favors a mixed population," said UT Austin psychology professor Robert Josephs. "Evidence of different social tactics are present across species, from beetles and spiders to salmon and orangutans." 




In a study published in Hormones and Behavior, researchers modeled status interactions in a monetary hawk-dove game. Like the chicken game in which two cars drive toward each other and the first to swerve to avoid the crash is dubbed the "chicken," the hawk-dove game allows players to adopt dominant (hawk) or subordinate (dove) strategies, for a monetary pay-off. If one player chooses hawk while the other chooses dove, the hawk receives a 4:1 larger payoff. If both players choose dove, both benefit equally, but moderately 2:2; if both players choose hawk, neither receives a payoff.
"Groups with more than one high-testosterone individual may experience high levels of status conflict that can undermine individual and collective outcomes, whereas groups that are mixed are more likely to form social hierarchies that improve coordination and foster adaptive collective performance," said the study's lead author and UT Austin psychology Ph.D. alumnus Pranjal Mehta, who is now an assistant professor of psychology at the University of Oregon.
Ninety-eight participants were divided into same sex partners. Saliva samples were taken before and throughout the game to measure testosterone levels as well as the stress hormone cortisol. Cortisol, in high levels, has been linked to submissive, avoidant behaviors, whereas in low levels, it has been linked to dominant and aggressive behaviors.
In 10 rounds of play, participants, as a whole, opted for hawk strategies half of the time, a number that did not differ between males and females that further supports the claim that an evenly mixed population of hawks and doves has been favored by evolution. However, participants with higher levels of testosterone chose hawk decisions much more often than those with low-levels. Further, participants whose cortisol increased during the game tended to opt for dove strategies, whereas those whose cortisol decreased made more hawk decisions.
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Unexpectedly, participants' self-reported satisfaction was positively associated with testosterone levels, but only among participants low in cortisol. This joint influence of testosterone and cortisol is consistent with a burgeoning literature on dual-hormone effects, in which the influence of testosterone is facilitated by low cortisol levels, but blocked by high levels of cortisol.
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Source-Eurekalert