6 sneaky tricks to make someone tell the truth

“Cross your heart and hope to die.” It sounds childish, but asking someone to place a hand on his heart while answering your questions could result in more truthful answers, finds a new study from Poland.

Because your mind associates the gesture with morality and forthrightness, touching your ticker primes your brain for truth-telling, explains study coauthor Michał Parzuchowski, Ph.D. But be warned: Parzuchowski says he doubts this tactic would work if you try it on someone who’s motivated to lie—like a lover who you suspect may be fooling around. It’s more useful in situations when someone might be tempted to lie or cheat, but isn’t that motived to bluff you, he adds. (For example: You ask your roommate if he took your dog to the park, or just around the block.)

Here are five more ways to coax the truth out of someone:

Ask in a text. 

People tend to respond more honestly in texts than in verbal phone conversations, shows a study from the University of Michigan. The researchers hypothesize that, since you don’t have to hear the emotional consequences of your honesty—like your friend’s disappointment when you tell him you can’t make his bachelor party—you’re more likely to be forthright over a text.

Take money off the table. 

When people are exposed to cash or finance-related words, they’re up to 46 percent more likely to lie than if they’re primed with language unrelated to money, shows a study from Harvard and Penn. If you’re trying to drag straight answers out of an employee or coworker, shift his mind away from financial considerations. Talk about his long tenure with your company, how much fun you both have hanging out with coworkers—anything to get his mind off the dollars and cents of the matter, the research suggests.

Spritz a little cleaner. 

You behave more honestly in clean-smelling environments, according to research from Brigham Young University. All the scientists had to do was spray a little lemon-scented Windex in the experiment room, and honesty jumped up to 90 percent among people asked to divide up some cash between themselves and someone else.

Shine a light. 

You’re less inclined to lie or act unethically in bright spaces, as opposed to dark rooms, shows research from Taiwan. How come? Your brain equates light with openness and honesty. And when a room is brightly lit, you feel like your thoughts and actions are exposed, the study authors explain. As a result, you’re 35 percent more likely to behave honestly.

Make him go the distance. 

When soldiers were told they’d earn an extra 30 minutes of leave on a Thursday evening for every point they scored in game of dice, they were much more likely to cheat on a Wednesday or a Thursday—as opposed to a Monday, reveals an Israeli study. Whatever motivates someone to cheat—whether it’s money, power, or sex—putting “temporal distance” (a.k.a. more time) between the lie and the payoff reduces the likelihood of dishonest behavior. If you want honest answers, try to widen the time gap between when you ask your questions and the possible payoff of a dishonest answer, the study suggests.