Say Cheese (or Get Divorced?)

Matthew Hertenstein, a psychology professor at DePauw University in Greencastle, Ind. and three colleagues recruited more than 600 people for a review of their college yearbook photos. The researchers rated the yearbook smiles by coding muscle movements around the mouth and the eyes.

The researchers found a surprising correlation: the less people smiled, the more likely they were to later divorce. The effect was statistically significant, though not huge. But when Hertenstein compared the top 10 percent of brightest smilers with the bottom 10 percent of weakest smilers, the "lowest were five times more likely to be divorced than the top."

[http://www.nytimes.com/projects/magazine/ideas/2009/#p-1]