UTA Logo The stress hormone cortisol was recently claimed to cause relapse in alcoholics. A new psychology research triggered by The University of Texas at Austin claims that elevated levels of cortisol plays a crucial role in blocking testosterone’s influence on competition and domination. Apparently this is the first research for highlighting two hormones testosterone and cortisol to control dominance.

Investigators showed that heightened cortisol, a hormone known to be released in the body in response to threat, enables the body to escape danger and not respond to any influence that testosterone is having on behavior. It was pointed out that hormonal axes work against each other to regulate dominant and competitive behaviors. Hormonal axes are believed to be complex feedback networks present between hormones and certain brain areas that govern testosterone levels and cortisol.

Robert Josephs, professor of psychology at The University of Texas at Austin and lead investigator, said, “It makes good adaptive sense that testosterone’s behavioral influence during an emergency situation gets blocked because engaging in behaviors that are encouraged by testosterone, such as mating, competition and aggression, during an imminent survival situation could be fatal. On the other hand, fight or flight behaviors encouraged by cortisol become more likely during an emergency situation when cortisol levels are high. Thus, it makes sense that the hormonal axes that regulate testosterone levels and cortisol levels are antagonistic.”

While conducting the investigation, scientists measured hormone levels of saliva samples accumulated by 57 subjects. Volunteers had to participant in a one-on-one competition and were given the opportunity to compete again after winning or losing. All those who lost revealed high testosterone and low cortisol, and requested a rematch to recapture their lost status. On the other hand, all the participants who won displayed high testosterone and high cortisol but denied to compete again. Subjects declining a rematch showed an extreme reduction in testosterone after defeat, so probably that’s why they were unwilling to compete again.

The findings may help scientists understand physiological effects of stress and the role they play in fertility problems. Chronically increased cortisol levels are believed to restrict testosterone production in men further causing impotence and loss of libido. Similar levels of cortisol are assumed to produce severe fertility problems and an abnormal menstrual cycle in women. Such effects can possibly be reversed when stress levels are decreased.

The research is published online in Hormones and Behavior.