Does testosterone influence success? Not much

Higher testosterone has often been linked to sporting and business success and most researchers have thought that the relationship between the hormone and success—particularly in men—was causal. If you are blessed with the genes that drove higher levels of the stuff into the right parts of the brain you were set for life (especially if you were male).

But now some important new research has found little evidence that testosterone meaningfully influences life chances for men or women. In fact, the study suggests that despite the social myths surrounding testosterone, it could be much less important than previously thought.

It is already known that in men, testosterone is linked with socioeconomic position, such as income or educational qualifications.  The present researchers wanted to find out whether this is because testosterone actually affects socioeconomic position, as opposed to socioeconomic circumstances affecting testosterone, or health affecting both.  The findings are published in Science Advances.

To isolate effects of testosterone itself, the research team applied an approach called Mendelian randomization in a sample of 306,248 UK adults from UK Biobank. They explored testosterone’s influence on socioeconomic position, including income, employment status, neighborhood-level deprivation, and educational qualifications; on health, including self-rated health and BMI, and on risk-taking behavior.  

What the researchers say: “There’s a widespread belief that a person’s testosterone can affect where they end up in life. Our results suggest that, despite a lot of mythology surrounding testosterone, its social implications may have been over-stated,” the lead researcher told us.

First, the team identified genetic variants linked to higher testosterone levels and then investigated how these variants were related to the outcomes. A person’s genetic code is determined before birth, and generally does not change during their lifetime (though particular gene expressions may in reaction to experience and context). This makes it very unlikely that these variants are affected by socioeconomic circumstances, health, or other environmental factors during a person’s lifetime. Consequently, any association of an outcome with variants linked to testosterone would strongly suggest an influence of testosterone on the outcome.

In line with previous studies, the researchers found that men with higher testosterone had higher household income, lived in less deprived areas, and were more likely to have a university degree and a skilled job. In women, higher testosterone was linked to lower socioeconomic position, including lower household income, living in a more deprived area, and lower chance of having a university degree. Consistent with previous evidence, higher testosterone was associated with better health for men and poorer health for women, and greater risk-taking behavior for men.

In other words, there was a strong association between a man’s level of the hormone and his level of success.

What they found in this study was there was little evidence that the testosterone-linked genetic variants were associated with any outcome for men or women. Testosterone did not cause success. There was little evidence that testosterone meaningfully affected socioeconomic position, health, or risk-taking in men or women. The study suggests that—despite the mythology surrounding testosterone—it might be much less important than previously claimed.

“Higher testosterone in men has previously been linked to various kinds of social success,” the researchers said. “A study of male executives found that testosterone was higher for those who had more subordinates. A study of male financial traders found that higher testosterone correlated with greater daily profits. Other studies have reported that testosterone is higher for more highly educated men, and among self-employed men, suggesting a link with entrepreneurship.

“Such research has supported the widespread idea that testosterone can influence success by affecting behavior. There is evidence from experiments that testosterone can make a person more assertive or more likely to take risks—traits which are usually rewarded in the labor market, for instance during wage negotiations. But there are other explanations. For example, a link between higher testosterone and success might simply reflect an influence of good health on both. Alternatively, socioeconomic circumstances could affect testosterone levels. A person’s perception of their own success could influence testosterone: in studies of sports matches, testosterone has been found to rise in the winner compared to the loser.”

So, what? What the researchers have found, essentially, is that testosterone levels in men are associative with success and not a cause of it. In fact, it may be the other way around: success may cause a rise in their testosterone levels. As long as that success persists, male testosterone will remain at elevated levels.

Just as interesting are the differences researchers have found in the effect that testosterone and success have on each other in women. That needs more study although, like with men, the effect on women is unlikely to be directly causal rather than associative.