RACHEL MARTIN, HOST:
Here's a question - have you ever done a really big workout at the gym, then gone home and gorged yourself on the first unhealthy thing you can find? New research explores why you chose to do that. NPR's social science correspondent, Shankar Vedantam, is here to explain. Shankar, I know none of this.
SHANKAR VEDANTAM, BYLINE: (Laughter).
MARTIN: I've never ever done this - worked out and then pigged out. I mean, this is - I do this constantly. And I feel like I've just worked out, and so why can't I have a double cheeseburger?
VEDANTAM: That's exactly right. Now, researchers have a term for this, Rachel. They call it licensing. And we've actually talked about other examples on the show. I was talking to Aaron Garvey. He's a consumer psychologist at the University of Kentucky. Here's how he described the phenomenon to me.
AARON GARVEY: Whenever somebody does something virtuous, they then feel liberated to go and pursue things that are less virtuous. So you engage in virtuous behavior, and you then are less guilty or you feel less guilty about engaging in this vice behavior.
VEDANTAM: But in some new research, Garvey and his colleague Lisa Bolton, Rachel, have discovered a new twist to this phenomena.
MARTIN: OK. Do tell.
VEDANTAM: Well, we'd always thought licensing works through the process you describe. You think to yourself, as you said, I've worked hard. I deserve something nice. Garvey and Bolton designed a study to test this. They wanted to better understand what causes licensing. They brought volunteers into a lab and gave them cookies to eat. All the volunteers had the same kind of cookie, but one group got cookies that were labeled healthy. The volunteers were then allowed to eat as much candy as they wanted while watching movie trailers, and the researchers measured how much candy they ate. Volunteers who thought they ate the virtuous and healthy cookie ate more candy. But here's the twist - it wasn't because they thought they deserved it. It's because the taste of the candy changed.
GARVEY: What we found was that there was an increase in the experienced pleasure derived from eating the candy. Taste was actually heightened for individuals in the virtuous consumption condition.
MARTIN: OK, so, Shankar, you're telling me that after I work out, for example, the food I eat, that double cheeseburger, actually tastes more delicious?
VEDANTAM: That's right. And so it's not surprising, of course, that more people would want to indulge themselves. Garvey thinks there are two implications of this research, Rachel. One, if you want to heighten your pleasure from food or drink, do something difficult and virtuous beforehand, and your food will actually taste better. Second...
MARTIN: Like, if you're about to eat a mediocre meal, you should just go run...
MARTIN: ...On the treadmill. And all of a sudden, those Brussels sprouts - delish (ph).
VEDANTAM: I think that's exactly what he's saying. But the second implication might actually be more important. If you don't want your efforts to eat right or live right to be undermined by licensing, tell yourself you aren't just gritting your teeth to do the right thing but that you're actually emotionally committed to the task or activity. The less you feel you have to force yourself to do the right thing, the less likely you are to fall victim to licensing.
MARTIN: OK. I think this means I can eat more cheeseburgers, and they will taste better. And maybe I have to work out, but maybe I don't.
VEDANTAM: I don't think that's what I said at all.
MARTIN: OK, we're due a follow-up conversation on that then. Shankar Vedantam - he covers social science for NPR. He explores this and other ideas on his podcast Hidden Brain. Thanks, Shankar.
VEDANTAM: Thanks, Rachel.
(SOUNDBITE OF MY DAD VS. YOURS'S "TANZ MIT UNS")