When we have a question about something embarrassing or deeply personal, many of us don't turn to a parent or a friend, but to our computers: We ask Google our questions.
As millions of us look for answers to questions, or things to buy, or places to meet friends, our searches produce a map of our collective hopes, fears, and desires.
Seth Stephens-Davidowitz, a former data scientist at Google, analyzes the information we leave behind on search engines, social media, and even pornography sites. He's the author of the book Everybody Lies: Big Data, New Data, and What the Internet Can Tell Us About Who We Really Are.