2015考研英语阅读色情与政治_大学英语阅读

2015考研英语阅读色情与政治

　　这至少是宾夕法尼亚州Villanova大学的 Patrick Markey和他在新泽西州Rutgers工作的妻子Charlotte的研究得出的结论。Markey夫妇正致力于寻找一种被称为挑战假说现象的证据。这种挑战假说现象称，卷入竞争的雄性动物在获胜后会经历一个睾丸激素水平上升的过程反之则相反。

　　The challenge hypothesis was first advanced to explain the mating behaviour ofmonogamous birds. In these species, males testosterone levels increase in the spring, topromote aggression against potential rivals. When the time comes for the males to settledown and help tend their young, their testosterone falls, along with their aggressivetendencies.

　　这种挑战假说首次提出是用来解释单配鸟类的性行为的。在这些物种中，雄性的睾丸激素水平在春天会上升，以提升进攻能力震慑潜在对手。当这些雄性需要安家并照料幼崽的时候，随着他们攻击倾向的消退，睾丸激素也下降了。

　　Something similar has since been found to apply to fish, lizards,ring-tailed lemurs, rhesusmonkeys, chimpanzeesand humans. In many of these animals, though, there is a twist. Itis not just that testosterone ramps up for breeding and ramps down for nurturing. Rather,itsproduction is sensitive to a male s success in the breeding competition itself. In men, then,levels of the hormone rise in preparation for a challenge and go up even more if thatchallenge is successfully completed. Failure, by contrast, causes the level to fall.