In a study published this week, and one that is sure to rekindle the Facebook privacy fire, researchers have shown that Facebook users are unknowingly revealing everything about themselves through their likes.

Funded by Boeing and Microsoft Research, the study shows that Facebook can be used to accurately predict a wide range of personal attributes including: sexual orientation, ethnicity, religion, political opinions, personality traits, substance use, and age and gender. You can even tell researchers whether or not your parents separated when you were 21.

The average person has 170 likes on their profile and demonstrates how looking at the basics of the information a person provides online develops an automatic and accurate estimate of what that person is like.

Although the same could be said when looking at a person’s Google history, web browsing, or Twitter subscriptions, the only difference here is that Facebook likes are currently publicly available by default.

58,466 volunteers participated in the study by offering their Facebook like data obtained through a Facebook application.

The study was able to correctly predict whether:

• 95% of the cases were African American or Caucasian American.
• 93% of the cases were women or men
• 82% of the cases were Christian or Muslim.
• 67% of the cases were single or in a couple.
• 73% of the cases were smokers or not
• 65% of the cases were drug users or not
• 60% of the cases were the parents of separated users when they were 21 years old or not.

He goes on to show how personality traits were a bit more difficult to predict accurately, as they could only predict them correctly:

• The emotional stability of users in 30% of cases
• The opening of users in 43% of the cases
• User satisfaction with life in 17% of cases

To explain the lower precision of the ‘life satisfaction’ trait, the researchers say, it’s difficult to separate long-term happiness with variable mood swings on Facebook.

People post less when they’re happy, but they give them something to complain about and they go off like a rocket.

It also showed that people who liked ‘Hello Kitty’ tend to have high openness and low emotional stability.

They have created a website where users can test the look of personality traits for themselves at youarewhatyoulike.com.

With a Facebook “Like” button gracing almost every website (and still growing), it can be hard to avoid the pull of clicks. What to express your feelings.

Interestingly, the study shows how tastes and individual traits are correlated. For example, they found that the best predictors of high intelligence include ‘thunderstorms’,’ potato chips’, and The Colbert Report. ‘ Good predictors of male homosexuality were ‘No H8 Campaign’, ‘Mac Cosmetics’ and ‘Wicked the Musical’. Likes ‘Britney Spears’ and ‘Desperate Housewives’ was considered moderately indicative of being gay, while people who liked ‘Being confused after waking up from naps’ were more likely to be straight men.

It will be interesting to see, moving forward with this study, if companies begin to use it to tailor their ads and services more to the individual than to the whole, and how the publication of this study will serve to further the debate on privacy in the digital age.