Next time you find yourself in a bad mood, don’t try to put on a happy face—instead tackle a project that has been stymieing you. Melancholy might just help you hit peak performance, reports Joseph Forgas, a professor of psychology at the University of New South Wales, in the journal Australasian Science. Forgas reviewed several of his studies in which researchers induced either a good or bad mood in volunteers. Each study found that people in a bad mood performed tasks better than those in a good mood. Grumpy people paid closer attention to details, showed less gullibility, were less prone to errors of judgment and formed higher-quality, persuasive arguments than their happy counterparts. One study even supports the notion that those who show signs of either fear, anger, disgust or sadness—the four basic negative emotions—achieve stronger eyewitness recall while virtually eliminating the effect of misinformation. [For more on how a negative mood boosts cognition, see “Depression’s Evolutionary Roots,” by Paul W. Andrews and J. Anderson Thomson; Scientific American Mind, January/February 2010.]