If you think by making your profile private on Facebook, you’d be hiding key information about yourself, you’d be wrong. A new study from Cambridge University has found that just by analysing your Facebook “Likes” activity, they can find out everything from your sexual orientation to your IQ. And yes, the information as to which pages you like on Facebook is one hundred percent public.

The Cambridge University team analysed the Facebook profiles of 58 000 users and their likes. With almost perfect accuracy they were able to find out information that most people wouldn’t like to public. How about sexual orientation? The study revealed that pages like “Kathy Griffin”, “Mac Cosmetics” and “Wicked The Musical” were signs of a homosexual male, whilst “X Games” and “Bruce Lee” revealed the male to be heterosexual.

High IQ scores were relegated to those who liked pages such as “Lord of the Rings” and “To Kill a Mockingbird” whilst their lower IQ counterparts seemed to like “Sephora” and “Harley Davidson.”

The Facebook users tested volunteered their real information so that their “Likes” could be measured against their personality test results and demographic profiles.

The information these pages is used to better target users for certain advertising and News Feed activity on Facebook. For marketers, you can pick and choose everything from someone’s religion to political views to narrow down your target audience.

This is nothing new on Facebook, but it does show just how private (or not) your information online truly is. It also reveals just how effective marketing on social media platforms like Facebook can be.