Article here. Excerpt:
'He's Hormonal. Alpha males are high on testosterone, the hormone that underlies almost all the typical traits of the politico-sexual animal: high levels of testosterone make for a high sex drive, a love of risks, aggressiveness and competitiveness. "These people have a strong need to win at games, which is obviously important in power politics," says Zuckerman. Success sends their testosterone spiraling up, while a loss brings the levels down— a phenomenon that's been documented in the lab as well as in athletes and chess champions.
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Women's testosterone levels also rise when there's competition on the line, but the actual act of winning—or, for that matter, losing—doesn't have any effect on the levels either way. It's the game, not the outcome, that makes the difference for women. Success, then, may not set them off-balance the same way. Evolutionary psychology also suggests that women leaders wouldn't be as likely as men to get caught in sex scandals. "Men and women play different roles in reproduction, so I don't think that you'd see the same kind of pattern where high-status women would be more likely to seek out lots and lots of men," says Daniel Kruger, a research scientist at the University of Michigan who has studied risk-taking behavior. "That's not going to really benefit them that much because they're limited in the number of children they could have." Men, on the other hand, have more of a biological imperative to spread their genes far and wide--the kind of privilege that often comes with being an alpha male.'