Want to predict the long-term prospects for your marriage? Check those gap-toothed birthday party photos from your spouse's childhood.
A newly published study finds a strong link between people's "smile intensity" in childhood or college yearbook photos and the likelihood they'll divorce at some point.
"The fact that you can determine a major life outcome such as divorce from a snapshot decades earlier in a person's life is pretty surprising to me," says author Matthew Hertenstein, an associate psychology professor at DePauw University in Indiana.
The researchers examined 847 college yearbook photos from about 650 people who were 21 to 87 years old at the time of the study.
They "painstakingly coded" people's smiles by examining the contractions of the zygomatic major muscle, which pulls up the corners of the mouth, and the orbicularis oculi muscle, which gives you "that twinkle in the eye," Hertenstein says. The researchers assigned one to five points for each muscle group, he says, based on how much the corners of the mouth were pulled up and the amount of crow's feet around the eyes.
When they matched those smile scores with people's marital histories, the results were striking.
On average, the Mona Lisa types were five times more likely to have been divorced than the 10 per cent with the toothiest grins, he says.
They also examined 217 personal snapshots of another 55 people, photos taken when they were between five and 22 years old, and got similar results.
"We found the same exact patterns with three different samples, so I'm convinced this isn't a fluke," Hertenstein says
However, he cautions that the researchers also found plenty of smiley people who had been divorced and plenty of stone-faced people in long-standing relationships, so their findings only point to relative likelihood.
The study is published in the June issue of the journal Motivation and Emotion.
As for why decades-old pictures reveal people's later likelihood of achieving household harmony, Hertenstein says he thinks the most likely explanation is that people who smile more have a "rosier" disposition that buffers relationship ups and downs. It's also possible that they attract others with similarly sunny personalities, he says. Or maybe it's not about the smile at all.
"Maybe people who smile when they're told to by the photographer are more obedient, and maybe obedience leads to happier relationships," he says, laughing.
-- Canwest News Service