Most people think they can, but they're wrong.
In study after study, subjects have been unable to distinguish between videotaped liars and truth tellers, scoring little better than chance. Human beings, as it turns out, have too much faith in themselves. The detection of falsehood is scarcely the only domain where they overestimate their abilities. Similarly, most people think they are likely to live longer than the mean. In a classic 1977 paper in the Journal of Experimental Psychology, Baruch Fischhoff, Paul Slovic, and Sarah Lichtenstein reported that people often pronounce themselves absolutely certain of beliefs that are untrue.