06/13/2012 10:31 am ET Updated Jun 13, 2012

Yearbook Photos Reveal Gender, Ethnic Differences In Smiling: Study

You may not have your dad's sense of style, but what about his smile? As you peruse those old photos this Father's Day, consider this:

In a study of more than 18,000 yearbook photos, psychologists Taylor Wondergem and Mihaela Friedlmeier confirmed what previous research has shown -- that women smile more frequently and more broadly than men. The research also brings an idea to the masses that has long been common knowledge to some -- black men don't smile in pics.

Why that is, is something the study authors could only guess, but first, they looked into when the distinction starts to occur.

From photos taken at 17 schools in Michigan and spanning kindergarten through the twelfth grade, Wondergem and Friedlmeier concluded that boys start smiling less than girls in their yearbook photos by the time they reach the sixth grade, findings they published in the journal Sex Roles in April of this year.

What's more, the research uncovered bigger differences in smiling between African-American boys and girls than between European American boys and girls, in a component of the study that sought to explain ethnic differences in smiling and how the level of diversity within each school factors in.

"It's particularly interesting that African-American boys from schools with a predominantly African-American student population showed less smile compared to those from ethnically mixed schools and those with a majority of European American students," study author Mihaela Friedlmeier told MSNBC, pointing to the different image of masculinity each group of boys may be getting and an internalized effort to avoid the "Uncle Tom" imagery of the smiling black men that may have been passed on from their parents and their peers.

African-American girls, on the other hand, smiled only a little less than their European-American peers, a difference that researchers say is far more slight because both groups of girls are influenced by similar cultural norms when it comes to standards of beauty.

A similar study last year found that smiling men were considered less attractive to women, offering another possible explanation and sparking conversation on how that might encourage people to start dating outside of their race.

Or perhaps there's a simple, genetic factor at play. Could the old "like father, like son" theory be true?



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