Some “friends.” Your Facebook pals could be making you depressed! A study of more than a billion status updates found that they’re contagious- negative posts inspire more negative content. And what’s more, this powerful emotional effect can be seen worldwide. Researchers found that when people in a place experiencing rain posted negative updates about the weather, those posts influenced Facebook users in places where the sun was shining. Fortunately, it works both ways- upbeat posts give rise to more positive content.