The Internet isn’t making us dumb. It’s making us angry.

In a study of 70 million posts on Sina Weibo, China's version of Twitter, Rui Fan and a team of others at Beihan University tracked the spread of joy, sadness, anger and disgust across the social network. According to the MIT Technology Review, they found that angry tweets were far more likely to be retweeted by others — or be the subject of angry responses — up to three degrees away from the original user. Joy, disgust and sadness weren't nearly as influential over others, the researchers learned.