Women, testosterone and finance
Risky business
From The Economist print edition
Hormones, not sexism, explain why fewer women than men work in banks
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THAT the risk-taking end of the financial industry is dominated by men is unarguable. But does it discriminate against women merely because they are women? Well, it might. But a piece of research just published in the Proceedings of the National Academy of Sciences by Paola Sapienza of Northwestern University, near Chicago, suggests an alternative—that it is not a person’s sex, per se, that is the basis for discrimination, but the level of his or her testosterone. Besides being a sex hormone, testosterone also governs appetite for risk. Control for an individual’s testosterone levels and, at least in America, the perceived sexism vanishes.
Dr Sapienza and her colleagues worked with aspiring bankers (MBA students from the University of Chicago). They measured the amount of testosterone in their subjects’ saliva. They also estimated the students’ exposure to the hormone before they were born by measuring the ratios of their index fingers to their ring fingers (a long ring finger indicates high testosterone exposure) and by measuring how accurately they could determine human emotions by observing only people’s eyes, which also correlates with prenatal exposure to testosterone.
The students were then presented with 15 risky choices. In each they had to decide between a 50:50 chance of getting $200 or a gradually increasing sure payout, which ranged from $50 up to $120. (Some of this money was actually paid over at the end of the experiment, to make the consequences real.) The point at which a participant decided to switch from the gamble to the sure thing was reckoned a reasonable approximation of his appetite for risk.
As the researchers suspected, women and men with the same levels of testosterone generally switched at the same time, demonstrating similar risk preferences. In other words, women who had more testosterone were more risk-loving than women with less, while the data for men at the lower end of the spectrum displayed a similar relationship. Curiously, the relationship between testosterone and risk taking was not as strong for men with moderate to high levels of the stuff, though previous studies have shown this relationship can be significant as well.
In all cases the correlation was strongest when the salivary measure of testosterone was used, suggesting that it is the here and now, rather than the developmental effects of testosterone on the brain, that is making the difference.
The researchers then followed the subjects’ progress after they graduated, to see what sort of careers they entered. As expected, men were more likely than women to choose a risky job in finance. Again, though, the difference was accounted for entirely by their levels of salivary testosterone. The researchers also studied the subjects’ personal investment portfolios after they had graduated, once in June 2008 (pre-crash) and again in January 2009 (post-crash). In a paper that has yet to be published, they demonstrate that the riskiness of these portfolios, too, was strongly correlated with subjects’ responses in the lottery game. The past year has, presumably, been kind to those with low testosterone levels.
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Sexual selection in humans
Mr Muscle
From The Economist print edition
The price and privilege of beefcake
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The way to hook the ladies? |
WHY are men’s muscles so much bigger than women’s? Partly, of course, because men do the fighting and hunting. But also, perhaps, because women like men who can do these things well, and are thus attracted to muscular men. Both phenomena—competing with members of the same sex and showing off to members of the opposite—are subject to a form of evolution known as sexual selection. It is sexual selection that created the deer’s antlers and the peacock’s tail, and William Lassek of the University of Pittsburgh and Steven Gaulin of the University of California, Santa Barbara, think it explains men’s muscles as well.
The main characteristic of sexually selected features is that they are expensive to maintain. Since, whether competing or attracting, only the best will do, resources get piled into them, almost regardless of the consequences. In a study just published in Evolution and Human Behavior, Dr Lassek and Dr Gaulin show that this crucial characteristic is true for men’s muscles.
Their data came from the National Health and Nutrition Examination Survey, which followed 12,000 American men and women over the course of six years. They found that men require 50% more calories than women do, even after adjusting for activity levels, and that their muscle mass is the strongest predictor of their intake of calories—stronger than their occupation or their body-mass index (a measure of obesity). And there is another cost to being muscly: men’s immune systems are less effective than those of women (which was known before), and become worse the more muscular the men are (which was not).
The benefits, however, were there, as well. The more muscular a man, the more sexual partners he reported, both in the past year and over his lifetime, and the earlier his first sexual experience was likely to have been. This may, in part, be a result of the ability of muscular men to intimidate 97lb weaklings. But in a society where extreme forms of such intimidation are curbed by law, female choice seems as likely an explanation—especially as previous studies have confirmed scientifically the everyday observation that women do indeed prefer men with big biceps and triangular torsos.
Because muscles come at such cost, Dr Gaulin thinks an evolutionary fight is going on between natural selection, which conserves metabolic expenditure and promotes longevity, and sexual selection, which willingly trades both for extra mating opportunities. This may explain why men have such a range of muscularity. In the past, the strong man would have had better mating opportunities in the short term, but the skinny guy who outlived him could have had just as much reproductive success over the course of his longer life.
The irony for the skinny guy is that the laws which protect him from aggression also make it less likely that the hulk will fight himself into an early grave. Modern medicine, meanwhile, means the hulk’s weakened immune system is less likely to expose him to lethal infection. Time, then, to get the weights out, and start pumping iron.
| Copyright © 2009 The Economist Newspaper and The Economist Group. All rights reserved. |





We
are all chasing happiness. We talk of it as if it were real, a place
the budget airlines will surely soon be flying to, or a new product –
iPhoria? – that will hit the shelves any day. We sniff at mere
contentment. Disgruntlement we see as aberration. And being down in the
dumps is a certifiable disease.

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