Study suggests brown-eyed people appear more trustworthy

Brown-eyed people may appear to be more trustworthy than people whose eyes are of a different color, a new study has suggested. However, before you think of going out to buy brown-tinted contact lenses, keep this in mind too: the study said the eye color is not the only factor that evoked such trust. “It was unexpected that some superficial sign like eye color could somehow be linked, by means of genes and hormones, to facial shape,” said Karel Kleisner, a history of science professor at the Charles University in Prague and lead author of the new study published Jan. 9 in PLoS One, according to a report on Wired.com. “(But) I’d warn against any social application of the research. I don’t want to cause problems between employers and employees,” Kleisner added. Also, the study showed factors other than eye color that evoked trust, including particular facial features such as chin shape and mouth position. The study gauged the reactions of Czechoslovakian college students who were shown photographs of their peers. Kleisner speculated the "generally rounder, wider-mouthed, corner-upturned mouths of brown-eyed men look like they’re on the verge of smiling," and happy faces tend to inspire trust. Link between face structure, eye color Wired.com said Kleisner and colleagues had noticed in their earlier research work an apparent link between face structure and eye color in the Czech population. They showed the research subjects – 238 undergraduate students – pictures of 40 male and 40 female students, split equally between blue- and brown-eyed. "Brown-eyed men were consistently judged more trustworthy than blue-eyed men. The same trend held for women, but it wasn’t so pronounced," Wired.com said. However, when the researchers manipulated the images to change brown eyes to blue and vice versa, a second group of students shown the altered images judged the blue-eyed men as more trustworthy. This led the researchers to conclude that "facial shape and not eye color guided viewers’ impressions." A profile they drew up of brown-eyed people showed they had rounder faces, broader chins and wider mouths that turned up at the corners. In contrast, a profile of blue-eyed people showed they had more angular, long-chinned, narrow-mouthed faces. Yet, Kleisner said such a quick impression of trustworthiness should not necessarily be taken as a guide to real-world, real-time impressions. He suggested facial expression and body language are likely far more relevant, though not necessarily reliable. Evolutionary new trait Wired.com said the study was hard-pressed to explain the biological underpinnings of links between eye color and face structure, especially the connection between long, angular features and blue eyes. This was an evolutionarily new trait that arose about 10,000 years ago in Europe. "Genetic theory predicts that links between eye color and facial shape should dissolve over evolutionary time, washed out in the repeated genomic mixings of reproduction. That clearly hasn’t happened in this population," Wired.com said. The new study’s authors, among them anthropologist Peter Frost of Canada’s Laval University, who specializes in recent human evolution, think some as-yet-unidentified link between eye color, prenatal hormone exposures and historical mate preferences could be responsible. Tests elsewhere Scientists want to see whether the trends they noted are common across ethnicities and cultures. They have started tests of facial preferences in Cameroon, Romania, Turkey and the United Kingdom. “The research should be repeated in other age groups, in different countries,” said Kleisner, who said the findings thus far should be considered interesting ideas, not explanations for human behavior. — LBG, GMA News