"What a tangled web we weave, when first we practice to deceive," the old saying warns. But it turns out that moral and logistical challenges aren't the only problem with lying. Modern science shows being dishonest actually changes your brain, and not for the better. 

More lies equals less EQ.  

To figure this out a team of researchers led by Julia Lee of the University of Michigan conducted a series of experiments in which 259 volunteers were either quizzed about their level of honesty or asked to play games designed to give them the opportunity to cheat to win small cash prizes. Participants also completed a standard psychological test to measure their accuracy at reading other people's emotions from their facial expressions. The results were recently published in the Journal of Experimental Psychology and highlighted on the British Psychological Society Research Digest blog

No matter how the scientists ran the studies, they found the same result: the more a person lied the worse they were at reading other people's emotions. In short, dishonesty lowers your EQ

Why might this be? This particular research couldn't say conclusively, but the researchers suggest that in order to protect ourselves from feeling bad about our dishonesty, we mentally distance ourselves from other people. We look away, emotionally and physically, from others to avoid feelings of guilt, and this may make it harder to understand and empathize with others. 

It's also unclear from this research how long the effects last. Does lying lower your EQ for a day, a month, or a year? No one knows. But what is clear is that lying will keep you from connecting to those around you, at least in the short-term. 

"Cheating can have significant personal costs by reducing our general understanding of the feelings of others," concludes BPS. Truth-challenged leaders should take note. Your willingness to bend the truth is likely making you more out of touch with your team. 

Another study makes these results even scarier. 

This isn't the first study to look at the mental effects of lying, and the results of this sort of  research are invariably grim. Another recent study led by Duke psychologist Dan Ariely found that thanks to changes in the brain, the more you lie, the easier it gets. Dishonesty, the study concluded, is a slippery slope, down which small untruths can snowball into a habitual lying habit. 

"The dangerous thing about lying is people don't understand how the act changes us," Ariely commented. 

Taken together these two results are particularly worrying. Not only does lying get easier with practice, but with each untruth you tell, you distance yourself a little more from your fellow humans. Your EQ suffers. The only obvious conclusion here is that you should seriously consider doubling down on your commitment to honesty. 

A few white lies now and again might seem like no big deal, but science suggests they can lead to a cascade of troubles that can greatly reduce your ability to empathize, connect, and lead.