Facebook’s Likes expose intimate details, personality traits of millions

of the analysis was striking. Study of the openness trait — the spectrum of those who dislike change to those who welcome it — revealed that observation of Likes alone is roughly as informative as using an individual’s actual personality test score.

Some Likes had a strong but seemingly incongruous or random link with a personal attribute, such as Curly Fries with high IQ, or That Spider is More Scared Than U Are with non-smokers.

When taken as a whole, researchers believe that the varying estimations of personal attributes and personality traits gleaned from Facebook Like analysis alone can form surprisingly accurate personal portraits of potentially millions of users worldwide.

They say the results suggest a possible revolution in psychological assessment which — based on this research — could be carried out on an unprecedented scale without costly assessment centers and questionnaires.

“We believe that our results, while based on Facebook Likes, apply to a wider range of online behaviors,” said Michal Kosinski, operations director at the Psychometric Center, who conducted the research with his Cambridge colleague David Stillwell and Thore Graepel from Microsoft Research.

“Similar predictions could be made from all manner of digital data, with this kind of secondary ‘inference’ made with remarkable accuracy - statistically predicting sensitive information people might not want revealed. Given the variety of digital traces people leave behind, it’s becoming increasingly difficult for individuals to control.

“I am a great fan and active user of new amazing technologies, including Facebook. I appreciate automated book recommendations, or Facebook selecting the most relevant stories for my newsfeed,” said Kosinski.

“However, I can imagine situations in which the same data and technology is used to predict political views or sexual orientation, posing threats to freedom or even life.”

“Just the possibility of this happening could deter people from using digital technologies and diminish trust between individuals and institutions — hampering technological and economic progress. Users need to be provided with transparency and control over their information.”

Thore Graepel from Microsoft Research said he hoped the research would contribute to the on-going discussions about user privacy: “Consumers rightly expect strong privacy protection to be built into the products and services they use and this research may well serve as a reminder for consumers to take a careful approach to sharing information online, utilising privacy controls and never sharing content with unfamiliar parties.”

David Stillwell from Cambridge University added: “I have used Facebook since 2005, and I will continue to do so. But I might be more careful to use the privacy settings that Facebook provides.”

— Read more in Michal Kosinski et al., “Private traits and attributes are predictable from digital records of human behavior,” Proceedings of the National Academies of Sciences (11 March 2013) (doi: 10.1073/pnas.1218772110)