Think your friends know you well? Researchers have developed a computer model that can judge someone’s personality more accurately than their friends and family — using nothing but the subject’s Facebook activity.

Researchers at the University of Cambridge and Stanford University tested their algorithm on more than 17,000 Facebook users, who completed a personality survey and provided the researchers with access to their “likes.” Many of their friends, colleagues and family members also completed a survey describing the users.

The survey rated each subject on the five OCEAN personality traits: openness, conscientiousness, extraversion, agreeableness and neuroticism. Then the researchers compared those results to the subjects’ Facebook activity to establish links between “likes” and specific personality traits.

Given enough data, the algorithm was better able to predict a person’s personality traits than any of the human participants. It needed access to just 10 likes to beat a work colleague, 70 to beat a roommate, 150 to beat a parent or sibling, and 300 to beat a spouse.