The Role of Testosterone
The role of Testosterone Because of the persistent sex differences in physical aggression among humans and other animals, many researchers have wondered if testosterone plays a role. Although both men and women have this “male sex hormone,” men usually have much higher levels than women. Research conducted on a variety of animals has found a strong relation between testosterone levels and aggression. Some research with humans similarly report a strong link. For example, one study found that college fraternities whose members tended to have higher testosterone levels were more rambunctious and exhibited more crude behavior than other fraternities. In contrast, fraternities whose members had lower testosterone levels tended to be more academically successful and socially responsible, and their members smiled more. Some studies have also shown a positive relationship between testosterone and aggression or aggression-related behaviors (such as competitiveness) in women.
Although many studies have supported this link between testosterone and aggression, other research suggests that the association between testosterone and human aggression is weaker and less reliable than expected. One complicating factor with testosterone is that while it may contribute to aggression, aggression can also cause increases in testosterone. Another complexity comes from the interaction of testosterone with other hormones. For example, some research suggests that the combination of high testosterone and low cortisol is what predicts aggression, perhaps particularly aggression in the context of status- seeking or dominance behaviors
