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Most of us know a thing or two about pushing buttons—intentionally making someone jealous, for example, or annoyed, or blisteringly furious. But if you're a researcher investigating anger, how do you get a roomful of eager volunteers suitably ticked off so you can stick their heads in a brain scanner? Or make them feel sheepish in order to analyze the facial expressions of embarrassment? Here are a few of the more, shall we say, creative techniques science uses for eliciting emotions:

• Anger: Researchers at Columbia University have provoked irritation by having students answer increasingly personal and insulting questions: "Do you ever hear bells?" "Which member of your family most seems to need psychiatric care?" "With how many men has your mother had extramarital relationships?"

• Disgust: In a series of studies, Paul Rozin, PhD, a professor of psychology at the University of Pennsylvania, asked subjects to drink water or juice into which he'd dropped (and then removed) a sterilized cockroach. Children will happily comply until somewhere between the ages of 4 and 7, when the disgust response kicks in; adults generally won't have any of it. At the University of Groningen, researchers have shown subjects images of a dirty toilet or films of an amputation.

• Embarrassment: Dacher Keltner, PhD, director of the social interaction laboratory at UC Berkeley, cites studies in his book Born to Be Good in which subjects are asked to suck on a pacifier in front of friends or to model bathing suits while an experimenter takes notes on a clipboard.

• Awe: Keltner leads subjects across the scenic Berkeley campus to the life sciences building and seats them next to a full-size replica of a five-ton, 25-foot-long Tyrannosaurus rex.

What can you do?

This last technique could be useful if you happen to have a dinosaur handy. (Awe, it seems, influences people to act on behalf of the greater good.) Otherwise there are one or two lab tricks with great practical relevance in real life. Yawning, several studies show, instantly relaxes you and increases empathy—a perfect thing to do before a date or during a fight. And putting on a happy face really does lift your spirits, according to years of research by Paul Ekman, PhD, author of Emotions Revealed. (You can also make yourself somewhat angry or afraid just by making those expressions.) So the next time someone insults you, give yourself a moment, take a deep breath, and smile.

Next: What he's really thinking