JUDY WOODRUFF:

Seth Stephens-Davidowitz has used data from Google to measure all sorts of human traits, from racism, to depression and insecurity.

He has written a book called "Everybody Lies." And, tonight, he shares his Humble Opinion on how what we see posted on social media often has nothing to do with the real picture.

Have a listen.

SETH STEPHENS-DAVIDOWITZ, Author, "Everybody Lies": I have spent five years studying human beings' darkest and weirdest thoughts. And it actually made me feel better.

I have analyzed Google search data to learn who we really are, and I frequently found out the world doesn't work like I thought it did.

We consistently lie to friends, family members, doctors, and surveys. But we are remarkably honest with Google. Google serves as digital truth serum, as a modern-day confessional.

So, where do you think anxiety is highest in the United States? Cities with overeducated, overthinking intellectuals? Not true. Google searches show us anxiety and panic attacks are highest in rural areas with more people with fewer years of schooling.

How about this one? Where do you think racism is most prevalent in the United States? I thought it would be the Deep South. Again, not true. The most common racist searches are for jokes mocking African-Americans. These searches are made the most in Upstate New York, Western Pennsylvania, and industrial Michigan.

What percent of Web site visits look for ways to change one's body are done by women? What's your guess? Ninety percent? In fact, men are almost as likely to visit sites looking for weight loss or plastic surgery.

Here's one that you will never guess. What is the most common search in India that begins "my husband wants"? Got your guess ready? It is, "My husband wants me to breast-feed him."

Of course, you would never see this on someone's Instagram feed. On social media, people try to make themselves look good. "The National Enquirer" sells more copies than "The Atlantic Monthly," but "The Atlantic Monthly" is 45 times more popular on Facebook.

I guess people want their friends to think they're more intellectual than they are.

When you study enough Google search data, it's hard to take the cultivated selves we see on social media too seriously. Sometimes, it's interesting to compare people's Google searches to social media posts.

Consider how people complete the phrase "my husband is." First, on social media posts, when people are presenting an image to their friends, the top five ways to complete this phrase are "the best," "my best friend," "awesome," "amazing," and "so cute."

Now, on Google, where people are anonymous, one of the top five is also "awesome," so that checks out. The other four, "mean," "a jerk," "gay," and "annoying."

There's a popular saying in Alcoholics Anonymous: Don't compare your insides to other people's outsides.

As we move our lives online, I propose a new mantra: Don't compare your Google searches to other people's Facebook posts.