(FILES) The logo of social networking Web site 'Facebook' is displayed on a computer screen in London, on December 12, 2007. (LEON NEAL/AFP/GETTY IMAGES)

Do you like your fries straight or curly? The answer may reveal more about you than you think.

According to a Cambridge University study published Monday looking at how much what people “like” on Facebook can reveal about who they are, people who openly declare their affinity for curly fries on Facebook tend to have higher IQs.

Click by click, Facebook users are building a surprisingly nuanced picture of themselves, even without filling out their social networking profiles. Researchers published the article online at the Proceedings for the National Academy of the Sciences, showing off how they were able to figure out traits such as gender, personality type, political views and sexual orientation of individuals based on what 58,000 Facebook users decided to “like” on sites around the Web.

All of the information in the study, the report said, was in the public domain.

Researchers found that they could, for example, correctly distinguish between gay and straight men on the site 88 percent of the time by analyzing the kinds of TV shows and movies they liked. It also found that few gay men — less than 5 percent in the study — identify with groups that openly declare their sexual orientation, so a man’s preference for “Britney Spears” or “Desperate Housewives” was more useful in predictions.

Similarly, the researchers also found that they could differentiate between drug users and non-drug users with about 65 percent accuracy based on their expressed public preferences.

The study even included “like” predictors that could tell whether users’ parents had separated when they were young versus whether they had not.

Researchers told the British paper that they hope this study raises users’ awareness about the kind of information they may not realize they’re sharing with a wider audience.

In some cases, the study said, this data could be beneficial to help improve marketing recommendations or in psychology research. But the study also raised concerns that it’s too easy to gather telling data about users without obtaining their permission.

“One can imagine situations in which such predictions, even if incorrect, could pose a threat to an individual’s well-being, freedom or even life,” researchers said in the study’s conclusion.

Facebook users can change the privacy settings on what they’ve liked through the site’s settings to keep their fry — or any other kind of preference — out of the public's reach.

(Washington Post Co. chairman and chief executive Don Graham is a member of Facebook’s board of directors.)

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