What you like on Facebook reveals plenty about you. | Reuters/Robert Galbraith

You are what you "like" on Facebook, a Stanford professor has found.

That may be an oversimplification, but according to Michal Kosinski, an assistant professor in organizational behavior at Stanford Graduate School of Business, our forays through the online world offer significant clues as to who we are. Kosinski, who holds a doctorate in psychology, studies the digital world, the human personality and well-being. The Stanford News Service recently interviewed him:

What are some of the key findings in your recent research?

The thing that was most surprising to me – and it's quite surprising to me still, three years since I first discovered it – is that our most intimate traits can be very easily predicted from a digital footprint, and a very general one as well, such as Facebook "likes."

One of our most surprising findings is that we could even predict whether your parents were divorced or not, based on your Facebook likes. Actually, when I saw those results, I started doubting my methods and reran the analyses a few times. I couldn't believe that what you like on Facebook could be affected by your parents' divorce, which could have happened many years earlier – we're talking here about people who might be 30 or 40 years old.

One of our most surprising findings is that we could even predict whether your parents were divorced or not, based on your Facebook likes. Michal Kosinski

There are many other intimate traits that are also predictable from your digital footprint: smoking, drinking, taking drugs, sexual orientation, religious and political views, and so on. Actually, everything we tried predicting was predictable to some degree, and quite often it was pretty accurate. You can check how much a computer can learn from your likes by visiting the website with a demo of our models.

The second surprising thing is that such a wide range of digital footprints can be used in predictions – even broad measures, such as the number of your friends, number of your likes, how many times you log in to Facebook, how many tweets you have. Each one of those measures is not a very strong predictor of anything on its own. But if you combine many different variables of this kind, each of them slightly predictive, the computer can get a very good idea of who you are.

If I only know someone based on what is publicly shared on social media, how well would you say I know the person?

You don't know them very well, especially when compared with how much a computer can learn about them. That's a striking thing. Few Facebook likes are so obviously linked with personality or other traits as to allow a human to use them in forming accurate judgments. Language used in status updates or tweets might be even less informative for us humans, as the amount of personality-related information contained in each individual like or word is very small. Computers, however, are very good at combining thousands or millions of subtle pieces of information to arrive at accurate predictions. We humans, with our limited ability to simultaneously process more than a few facts at a time, are rather bad at it.

Do people use social media to orchestrate a public image for themselves that is different from the reality?

I think it's not very different from what we do in other parts of life. We always try to monitor our behavior: we try to be kind to others, dress in a certain way, stress certain parts of our history, and try to avoid mentioning embarrassing facts. We're just always involved in a lot of image control when we interact with others.

I think that, in a way, Facebook and other social media might be conveying information that is closer to our true selves than what we reveal in a face-to-face interaction. It's rather easy for people to misrepresent themselves in, say, a half-hour-long interview or on a first date. It's much more difficult to monitor your appearances and opinions in years of your Facebook history.

Can social media be a vital way of alerting others when help is needed?

Certainly. First of all, just being on social media, I believe, makes people happier. Otherwise, I believe, people wouldn't use it so much. People love social media, sharing their lives on Facebook, receiving the likes. Facebook serves one of our most basic instincts: to socialize, gossip, and feel needed. The same instincts drive us to read celebrity magazines and watch soap operas. On Facebook, we can all be celebrities within our social circles, which, I think, makes people rather happy.

This story was originally published in Stanford Report on August 26, 2015. Christina Dong is an intern at the Stanford News Service.