Every day, millions of people click on Facebook "Like" buttons, boldly declaring their preferences for a variety of things, such as books, movies, and cat videos. But those "likes" may reveal more than they intend, such as sexual orientation, drug use, and religious affiliation, according to a study that analyzed the online behavior of thousands of volunteers.
Your preferences define you. Researchers have known for decades that people's personal attributes-gender, age, religion, sexual orientation, and personality type-correlate with their choice of products, concepts, and activities. Just consider the different populations at an opera and a NASCAR race. This is why companies are so eager to gather personal information about their consumers: Advertising is far more effective when it is targeted to groups of people who are more likely to be interested in a product. The only aspect that has changed is the increasing proportion of personal information that is available as digital data on the Internet. And Facebook has become a major hub for such data through its like button. A team led by Michal Kosinski, a psychologist at the University of Cambridge in the United Kingdom as well as at Microsoft Research, wondered just how much people's likes reveal about them.
The Likes data are public information. The hard part was getting the data on intelligence and other such attributes to compare with the likes. For that, Kosinski and his Cambridge colleague David Stillwell created a Facebook app called myPersonality. After agreeing to volunteer as a research subject, users of the myPersonality app answer survey questions and take a series of psychological tests that measure things such as intelligence, competitiveness, extraversion versus introversion, and general satisfaction with life. Kosinski and Stillwell not only get those data but also data from the user's Facebook profile and friends network. In return, users get a peek at their own information. More than 4 million people have volunteered already.