Researchers at Cambridge University have discovered that users' Facebook 'Likes' can accurately predict private personality traits, including sexual orientation, religious beliefs and intelligence.

Published in the journal Proceedings of the National Academy of Sciences, the team used a set of algorithms on 58,000 volunteers to predict religion, politics, race and sexual orientation.  The eerily accurate personality profiles made should "ring alarm bells" for users, privacy campaigners said.

The experiment was a simple one to do: all volunteers provided demographic information and psychometric tests, to which content the individual liked on Facebook was matched with through various algorithms.  These proved 88% accurate for determining male sexuality, 95% in distinguishing African-American from Caucasian-American and 85% for differentiating Republican from Democrat.  

In terms of religion, the algorithms accurately classified Christians and Muslims with 82% accuracy, those in relationships were differentiated 65% of the time, and people with substance abuse issues were distinguished 73%.

Simply put, the content you interact with on Facebook is pretty clear-cut in creating a fact sheet about the user: something which has been used by social media marketers from the beginning, and a somewhat powerful tool if used by those with criminal intent.

 

“We believe that our results, while based on Facebook Likes, apply to a wider range of online behaviours.” said Michal Kosinski, Operations Director at the Psychometric Centre, 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."

What is curious though, is that these attributions are never from the obvious connections.  Less than 5% of gay users liked pages such as gay marriage, for example.  Instead, the algorithms inspected your likes in media content and 'off-the-wall' pages to determine your personal profile.  This has created some rather strange connections between page likes and personality traits, such as "Curly Fries" with high IQ, or "That Spider is More Scared Than U Are" with non-smokers.

While it's easy to see this could be a new level for psychological assessment and population analysis, the somewhat concerning privacy angle overrides the potential excitement of this discovery.

“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.”

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.”