10 Things You Didn't Know About LyingS You're surrounded by lies, but most of what you think you know about them is probably — you guessed it — a lie.

1. You can't tell somebody is lying from their eyes

A liar always has shifty eyes and can't look you in the face. It's one of our most commonly-held beliefs, and it's completely wrong. Psychologists offered strong evidence of this after examining video footage of people who lied and didn't lie, noting how often they looked to the left and right, creating the "shifty eye" effect. There was no measurable difference between people who were lying and those who were telling the truth.

2. Nobody has ever found a lie detector that works

Despite the fact that lie detector test results are admissible in some courts as evidence, there is ample evidence that it is relatively easy to fool common lie detectors. Essentially, all lie detectors measure are levels of stress and anxiety — and, given that many liars are cool and practiced under pressure, this doesn't tell you much about how truthful they're being. Some have suggested that we use fMRI brain imaging for lie detection, but there is even less evidence that lies can be detected in that way. Interestingly, there is evidence that using transcranial magnetic stimulation can induce people to lie more often than they normally would. And there are a few other lie detectors that could one day be foolproof.

3. Liars often fool themselves, too

Though cheaters and boasters often seem like transparent liars to other people, it's very likely that they are actually fooling themselves. A study published in 2011 showed that people who cheated their way into better scores on tests nevertheless overvalued their own abilities — despite the fact that they knew they had cheated. In other words, it's just as easy to fool yourself with lies as it is to fool other people.

4. People usually lie when they are pressed for time

Lies are not usually premeditated acts of evil. The reality is that most people lie because they have to make a quick decision and don't have time to think about the social consequences of a falsehood. According to a psychological study published last year, people asked to make a snap decision will often lie or cheat for their own self-interest. University of Amsterdam psychology researcher Shaul Shalvi put it this way: "When people act quickly, they may attempt to do all they can to secure a profit—including bending ethical rules and lying. Having more time to deliberate leads people to restrict the amount of lying and refrain from cheating." When you consider the insane time pressures involved in trading on the stock market, this discovery sheds a lot of light on recent economic events.

5. Americans lie at least once a day — and believe they get away with it most of the time.

In a study which asked Americans to estimate how many times they lie, the average answer was once or twice a day. What's really interesting is that another study revealed that Americans also think that they get away with lying 56% of the time. This audacity about falsehoods could be related to the fact that the U.S. is dominated by Protestants — the same study found that Protestants believed they could get away with lying 55% of the time, while Muslims believed their lies would succeed only 47% of the time.

10 Things You Didn't Know About Lying

6. Lying may have evolved to facilitate cooperation

Once you think about it, this makes perfect sense. Humans had to cooperate early in their evolution in order to survive. But what's one really great way to secure other people's cooperation? As anybody who has ever watched Survivor knows, it's by deceiving other people about what your real intentions are. As the authors of a study published earlier this year in the Proceedings of the Royal Society B put it, "Tactical deception, the misrepresentation of the state of the world to another individual, may allow cheaters to exploit conditional cooperation by tactically misrepresenting their past actions and/or current intentions." Lies are one pillar of our greatest altruistic creation as a species, cooperation.

7. Two-year-olds can deliberately lie

Are children too innocent to make things up just to mess with you or get what they want? Nope. Humans develop the ability to lie soon after they learn to walk.

8. Compulsive lying makes you smarter

A psychological study published in 2005 offers some intriguing evidence about what happens in the brains of people who lie all the time. Perhaps not surprisingly, they have a lot more connective "white matter" in their prefrontal cortex, the brain region devoted to cognition and reason. Indeed, compulsive liars had 22-26% more white matter than a control group. Study leader Yaling Yang told NPR there might be a reason why:

The increase in white matter means that people who lie repeatedly and compulsively are better at making connections between thoughts that aren't connected in reality — like, say, "me" and "fighter pilot." Consequently, while some of us struggle to come up with reasons why we were late for work, or can't go out with someone we don't really like, Yang's liars impulsively serve up a heaping helping of excuses and stories, and fast.

"By having more connections," Yang says, "you can jump from one idea to another and you can come up with more random stories and ideas."

9. "Truth serum" does not actually prevent you from lying

Despite everything you've seen in movies, sodium pentathol or "truth serum" does not actually make people tell the truth. It simply causes people to spew an endless stream of information — some truth, some fantasy — because their mental filters have been temporarily removed.

10. Politicians have been liars since the dawn of Western civilization

In the West, we often think of ancient Greece as the forerunner to contemporary democracies. And as far back as the 400s BCE, there is ample evidence that politicians were liars. One of the most famous examples comes in the career of the politician Alcibiades, who was famous for defecting to whatever side was winning in the Peloponnesian War. An Athenian pro-war politician and strategist, he defected to Sparta, where he also pushed for war. Then he defected back to Athens again when things went bad in Sparta. His favorite political tactic was deception.