The human habit of overestimating other people’s happiness is nothing new, of course. Jordan points to a quote by Montesquieu: ‘If we only wanted to be happy it would be easy; but we want to be happier than other people, which is almost always difficult, since we think them happier than they are.’ But social networking may be making this tendency worse. Jordan’s research doesn’t look at Facebook explicitly, but if his conclusions are correct, it follows that the site would have a special power to make us sadder and lonelier. By showcasing the most witty, joyful, bullet-pointed versions of people’s lives, and inviting constant comparisons in which we tend to see ourselves as the losers, Facebook appears to exploit an Achilles’ heel of human nature. And women—an especially unhappy bunch of late—may be especially vulnerable to keeping up with what they imagine is the happiness of the Joneses.