DAVID GREENE, HOST:
Okay. So one thing we should take from Allison's piece, chunky bread helps keep blood sugar low, but when blood sugar gets too low, there can be problems. For one thing, you can get a little, shall we say, unpleasant.
KELLY MCEVERS, HOST:
That's one way to describe it. This next story is about an experiment that involved voodoo dolls, angry spouses and really unpleasant noise, all in service of defining one of our favorite words. Here's NPR's Rob Stein.
Here's NPR's Rob Stein.
ROB STEIN, BYLINE: A lot of us know what can happen when we get hungry: we get grumpy, irritable, sometimes even pretty nasty. There's even a name for this: hangry.
BRAD BUSHMAN: Which is a combination of the words hungry and angry, which indicates that hungry people are often cranky and angry people.
STEIN: That's Brad Bushman, a psychologist at Ohio State University. Bushman wanted to know why. Why do some hungry people get angry? Lots of studies have suggested one reason: blood sugar. It plummets when people haven't eaten for a while. But most of those studies involved strangers in the laboratory.
BUSHMAN: And so we wanted to look at intimate partners instead.
STEIN: Including couples who basically really like each other and get along pretty well. Would low blood sugar levels even turn them into frenemies? So Bushman taught 107 couples how to measure their blood sugar. And sent them home with something unusual.
BUSHMAN: A voodoo doll and 51 pins.
STEIN: That's right, a voodoo doll.
BUSHMAN: We told the participants this doll represented their spouse. And that every night before they went to bed they should stab the doll with pins depending on how angry they were with their spouse. So the more pins they put in the doll, the more angry they were with their spouse.
STEIN: For the next 21 days, they did that. And in The Proceedings of the National Academy of Sciences this week, Bushman reports what he found.
BUSHMAN: We found that people who had low levels of glucose stuck more pins in the voodoo doll than people who had high levels glucose. In fact, people in the lower 25 percent stuck more than twice as many pins in the voodoo doll compared to people in the upper 25 percent.
STEIN: But Bushman wanted to know something else, whether those angry feelings actually translated into nasty behavior. So he had them play a computer game that involved blasting their spouse with a really awful noise.
BUSHMAN: The noise is a mixture of noises of things that most people hate, like fingernails scratching on chalkboards, dentist drills, sirens. Here's, here's the noise.
(SOUNDBITE OF A SCREECHING SIREN SOUND)
STEIN: And it turned out that the lower their blood sugar on average, the more likely they were to really let their spouse have it with the noise.
BUSHMAN: Regardless of how good somebody's relationship is, when they're hungry they're more angry and they stuck more pins in the doll. And they were more aggressive by giving their partner louder and longer blasts of noise.
STEIN: Bushman thinks his findings could lead to new ways to help couples fight less.
BUSHMAN: What we conclude is that glucose is the food for the brain that we need to exercise self-control. And when peoples' glucose levels are low they are poorer at exercising self-control.
STEIN: Other researchers cautioned that low blood sugar isn't the only thing that can trigger anger - far from it. But Emil Coccaro at the University of Chicago says low blood sugar probably makes it harder for peoples' brain to regulate their emotions.
EMIL COCCARO: The brain only uses sugar for its energy needs. So when there's less sugar available, the neurons aren't going to function as well.
STEIN: Now, Bushman isn't recommending people keep candy bars around to prevent angry outbursts. They cause quick spikes in blood sugar that aren't very helpful. But there are other common sense things people can do.
BUSHMAN: The take-home message from this would be to make sure you're not hungry when you talk about important issues with your spouse.
STEIN: So, Bushman suggest couples grab a power bar or something else that will keep their blood sugar levels steady before discussing something that might make them angry.
Rob Stein, NPR News.
(SOUNDBITE OF MUSIC)
MCEVERS: Eat your breakfast. Don't get hangry. It's MORNING EDITION from NPR News.