Testosterone and Serotonin's Relationship to Aggression

There’s been a number of posts recently concerning testosterone’s relation to well-being, aggression, suicide etc… I thought this article may be of interest to some people here. It appears low serotonin may be more of a contributing factor towards aggression than high testosterone.


Studies link high levels of the male hormone testosterone to aggression-but elevated testosterone alone doesn’t account for aggressive behavior. In fact, successful athletes and businessmen tend to have high testosterone levels, without being any more violence-prone than their low-testosterone counterparts.

Paul C. Bernhardt suggests that testosterone may not act alone in promoting aggression. Rather, he suggests, aggressive men’s behavior may be influenced by high testosterone levels combined with low levels of the brain chemical serotonin.

Bernhardt notes that testosterone is linked more strongly to dominance in general than to aggression. But what happens, he asks, when a high-testosterone man is frustrated in his attempts to achieve dominance? Then, Bernhardt speculates, serotonin comes into play, because low serotonin activity is associated with hyperresponsiveness to aversive stimuli.

In short, Bernhardt theorizes, high testosterone levels encourage dominance-seeking behaviors, “which put the individual into situations in which frustration of dominance can occur.” When this happens, low serotonin levels result in a greater likelihood of an intensely negative emotional reaction, and, thus, a greater chance of aggressive behavior.

Bernhardt speculates that the hypothalamus and amygdala, “prominently associated with both testosterone and serotonin,” play a key role in aggressive responses to situations in which efforts at dominance are frustrated. He notes that “low serotonin levels have been found in the hypothalamus and the amygdala in aggressive animals,” and that “testosterone action in both of these brain structures has been shown to increase aggression in various animal species.”

“Influences of serotonin and testosterone in aggression and dominance: convergence with social psychology,” Paul C. Bernhardt, Current Directions in Psychological Science, Vol. 6, No. 2, April 1997, pp. 44-48. Address: Paul C. Bernhardt, Department of Educational Psychology, MBH 327, University of Utah, Salt Lake City, UT 84112.

I’ve heard of serotonin being considered as more of a social neurotransmitter. Something that contributes to win/win behaviours when it is high and win/loss when serotonin is low. Aggressive behaviour when serotonin is low does seem to support this theory.

So making some kind of analysis out of this information… Roid rage could be considered the presence of high testosterone with low serotonin. A high need for dominance combined with low percieved social status. And someone with major self-esteem issues(low percieved social status) taking androgens may make an asshole in to an even bigger asshole.

One might question whether it is low serotonin that matters, or a low serotonin to testosterone ratio. In such a case, raising testosterone without a corresponding increase in serotonin would indeed make you more of an asshole, full-stop… but if you still had enough serotonin, you might continue to be functional in society.

That seems to make sense. Testosterone may be responsible for the drive for dominance. Enough serotonin may be needed to manage this drive in a “social acceptable” way. It’s all conjecture though. The human brain is a very complex machine. I don’t think it can be reduced to the action of a few neurotransmitters and hormones.

Something to think about though. Could the proposed “T-man” on this site be an individual with high T AND serotonin. Someone who nurture’s win/win relationships. Not someone who is willing to step over another in their quest for success?