Mindf*ck: Cambridge Analytica and the Plot to Break America

by Christopher Wylie

In fact, a 2015 study by Youyou, Kosinski, and Stillwell showed that, using Facebook likes, a computer model reigned supreme in predicting human behavior. With ten likes, the model predicted a person’s behavior more accurately than one of their co-workers. With 150 likes, better than a family member. And with 300 likes, the model knew the person better than their own spouse. This is in part because friends, colleagues, spouses, and parents typically see only part of your life, where your behavior is moderated by the context of that relationship. Your parents may never see how wild you can get at a 3 A.M. rave after dropping two hits of MDMA, and your friends may never see how reserved and deferential you are in the office with your boss. They all have slightly different impressions of who you are. But Facebook peers into your relationships, follows you around in your phone, and tracks what you click and buy on the Internet. This is how data from the site becomes more reflective of who you “really are” than the judgments of friends or family. In some respects, a computer model can know a person’s habits better than they even know themselves—a finding that compelled the researchers to add a warning. “Computers outpacing humans in personality judgment,” they wrote, “presents significant opportunities and challenges in the areas of psychological assessment, marketing, and privacy.”