Big smiles early in life mean a person is less likely to end up divorced in adulthood—though that doesn’t mean that pouty-pusses are doomed to be alone. Researchers at Indiana’s DePauw University measured the “smile intensity” in two groups of photos—college students’ yearbook photos and childhood photos of Midwesterners. After measuring muscles around the eyes and cheeks in 655 yearbook photos, the scientists concluded that the stronger the smiling, the more apt people were to stay together. The top 10 percent of smilers had a 5.5 percent divorce rate, while 27 percent of the bottom 10 percent of smilers were divorced. Only 55 people participated in the childhood photo study, making it too small to analyze reliably, but the pattern seemed to hold.

“The bottom-line finding is that people who smiled more stayed together, people who smiled less were more likely to get divorced,” says Matthew Hertenstein, an associate professor of psychology at DePauw who led the study.

But—and this is a very big but—“the huge caveat to this is that there are individual differences," Hertenstein says. “We found many people who smiled a lot and got divorced, and we found many people who frowned who stayed married and had good relationships.”

Obedient people may be more likely to smile for the photographer when they're young and more likely to stick with a bad marriage later, Hertenstein says. Or it could be that smiley people are more optimistic and thus willing to hang in there and hope for the best. Or it could be that smiling people attract other temperamentally happy people, and that leads to more successful marriages.

Numerous studies have shown that optimistic people fare better in relationships and at work, and also are healthier, than those who are eternally grumpy. (For more on this, see Daniel Goleman’s groundbreaking book, Emotional Intelligence.)

What’s a parent to do with this information? I instantly thought of telling my often sober 5-year-old to paste a smile on it. But fake cheer clearly isn’t the answer. I asked Hertenstein what he thinks this means for parents. “I have a 3-year-old son. My wife and I talk a lot about this,” he says.

Here are three ways that parents can encourage their children to be aware of their own emotions and thus to influence them:

  • Help children think about how other people are feeling. Tell them when you’re tired, scared, or delighted. And ask, "How do you think he felt when you did that?"
  • Let children know that they have control over their emotions. One good question: Do you want this to be a happy day or a sad day? That’s particularly good for dealing with the frustrations of childhood, whether it’s a broken toy or a playground bully. The situation may not be what you hoped, but it doesn’t have to ruin the day.
  • Give children strategies to learn how to regulate their emotions. If Joey won’t share the toy, help think of good alternatives: You can play with other things, or you can ask Joey to let you play with it in five minutes. “Teaching that to kids ages K through 12 is really, really important,” Hertenstein says.

Learning to regulate emotions is good lesson for grownups, too. The weather’s not always sunny here at OnParenting Central. But when I remember to look for the joy in the day–daffodils in the backyard, a troupe of neighborhood girls happily making sand cakes–my frustrations magically fade. My next photo will be smilier!