For Centuries, psychologists, philosophers and students of human nature have been probing how and why humans lie. But it was only in the mid-1900s that the study of deception emerged as a subject of popular scientific inquiry.

From thousands of controlled scientific studies and the field research done during this relatively short period, researchers and criminal investigators have amassed a considerable body of knowledge about deception—and how to detect it.

Here are some of their most remarkable findings so far:

Humans are lied to as many as 200 times a day.

Social psychologist Jerald Jellison of the University of Southern California published this figure in his 1977 book, “I’m Sorry, I Didn’t Mean To, and Other Lies We Love To Tell.” The hard-to-believe figure, which of course includes the many innocent “white lies” we hear each day, was given further credence in a 2002 study by Robert Feldman of the University of Massachusetts, who found that on average, people told two to three lies in a ten-minute conversation. Humans detect lies with only 54% accuracy.

Our shockingly poor performance at lie detection is just slightly better than if we were to blindly guess. In all of the aggregated studies about how well we detect lies vs. truths, we have never fared better than 57% accuracy. The largest review, encompassing results from 206 academic studies that involved 24,000 individual judgments of lies and truths, found our mean performance to be 54%. Not even weather forecasters are that bad. Between 75% and 82% of lies go undetected.

Separate studies led by deception researchers Aldert Vrij and Bella DePaulo found that the overwhelming majority of lies went undetected. Of the lies we tell, 25% are for someone else’s sake.

Lies fall into three broad categories: those we tell for our own benefit, those that benefit someone else, and those that benefit both ourselves and others. A study published in the Journal of Personality and Social Psychology found that at least a quarter of the time, our lies are for another person’s benefit. How thoughtful of us!

Children begin deceiving as early as age 6 months.

Dr. Vasudevi Reddy of the University of Portsmouth identified 7 types of deception used by toddlers based on studies of 50 children and interviews with parents. For some, the deception began at 6 months with behavior such as pretend laughter, or crying when nothing was wrong just to get attention. Gorillas, fish, birds, even orchids engage in deception.

Humans aren’t the only species capable of lying, of course. What’s surprising is the extent to which other animals and even plants rely on deception to survive. In one comic example, the famous signing gorilla Koko blamed her pet kitten for ripping a sink out of the wall. Avoiding eye contact is the most presumed sign of lying around the world—even though it’s false.

A worldwide study led by researcher Charles Bond found that 72% of people cited avoiding eye contact or averting gaze as a sign of lying, more than any other indicator. Too bad it’s not true. Perhaps this is for part of the reason we’re so bad at detecting lies… we are focused on the wrong clues. People engaged in normal conversation only make direct eye contact 30-60% of the time. Law enforcement officials—including FBI agents, customs agents and judges— performed no better than the average person in detecting deception.

This shocking stat should put a big smile on a fraudster’s face. A study by Paul Ekman and Maureen O’Sullivan published in American Psychologist found that only members of the U.S. Secret Service consistently fared better than the average person’s 54% accuracy. If you’re an honest person caught up in an investigation, better hope the Secret Service is involved!

One in six juries reaches an incorrect verdict.

Now that we know the average person is only 54% accurate at detecting lies, and policeman and judges are statistically no better, this absolutely stunning headline from a 2007 Northwestern University study shouldn’t really come as a surprise. But that doesn’t make it any more acceptable. Training can improve a person’s lie detection ability by 25-50%.

Despite our poor track record at catching lies, all hope is not lost. Several independent studies have found that training in the verbal and nonverbal clues of deception can significantly raise a person’s lie detection capability.

Take advantage of the liespotting tips on this site and in the book, Liespotting, to improve your skills.