Here's one you don't hear everyday. Scientists allege it's possible to predict whose marriages will fail by looking at "smile intensity" in childhood photographs.

Researchers got 650 photographs of adults taken during their final year in school and measured the brightness of their smiles. The men and women were between 21 and 87, meaning some of the photos were 70 years old. The volunteers were then asked if they had ever been divorced. Those with the "weakest" smiled were more than three times as likely to have been through a divorce. A second experiment used pictures taken when people were as young as five and confirmed the findings.

"Maybe smiling represents a positive disposition towards life," said study leader Matthew Hertenstein, a psychologist at DePauw University in Indiana. "Or maybe smiling people attract other happier people, and the combination may lead to a greater likelihood of a long-lasting marriage. We don't really know for sure what's causing it."

What do you think? Are relationships determined by the intensity of a smile? Perhaps they're just not happy taking photographs. Could smiles really predict marriage?

Smiles Predict Marriage Success [Live Science]

Childhood Photos Could Hold The Secret To Your Marriage [Daily Mail]