<p>Facebook, your usefullness just <a href="http://www.newscientist.com/article/mg20026841.700-the-dizzying-diversity-of-human-sexual-strategies.html?full=true" target="_blank"><strong>doubled</strong></a>:</p> <div>&nbsp;</div> <p class="quote">It is not just prenatal testosterone that makes a difference. Peter Gray of the University of Nevada in Las Vegas and his colleagues found that saliva samples taken from married men and fathers contained lower levels of testosterone than in other men. Since testosterone is associated with competitive and mating behaviour in a wide range of mammals, the researchers proposed that lower testosterone in fathers allows them to channel more of their energy into their children (<em>Evolution and Human Behavior</em>, vol 23, p 193). In another study, however, Gray found that testosterone levels are higher in married men on the hunt for extramarital sexual relationships. So, are men with lower than average testosterone simply more likely to enter into a committed relationship, or does being in such a relationship lower men's testosterone levels? "In monkeys and rodents, we know the causal arrow goes both ways," says Gray. Although there is little data on humans, he believes it would be surprising if the same were not true of men.</p> Mairi Macleod | New Scientist facebook, sex, relationships the-feed 0 2008-11-28T11:30:43-05:00 <p>Men and women can accurately determine another person's sexual proclivities based on a single photograph.</p> 10 2894 you-can-t-hide-your-lyin-eyes 2008-11-28T11:30:50-05:00 true false false false false 2008-11-28T11:30:50-05:00 12 0 0