FRIDAY, April 27, 2012 (HealthDay News) -- People show more emotion on the left side of their face, and that may help explain why that side typically appears more pleasant to others, researchers say.
Scientists from Wake Forest University said the findings may also help explain why portraits painted by Western artists often feature left-side profiles. The report is scheduled for online publication in the journal Experimental Brain Research.
"Our results suggest that posers' left cheeks tend to exhibit a greater intensity of emotion, which observers find more aesthetically pleasing," study authors Kelsey Blackburn and James Schirillo, of Wake Forest University, wrote in a journal news release. The new findings support "the notions of lateralized emotion and right hemispheric dominance with the right side of the brain controlling the left side of the face during emotional expression," they added.
For the study, the researchers showed study participants black-and-white profile photos. Some of the profiles were original photos, while others were mirror-reversed images. Participants rated the pleasantness of both sides of people's faces.
The results showed that the left side of both men's and women's faces were more aesthetically pleasing. This was true for the original photos as well as the mirror-reversed images.
Because people's pupils enlarge or dilate in response to interesting stimuli, the researchers confirmed their findings by measuring participants' pupil sizes. They found pupil size increased along with pleasantness ratings.
The American Psychological Association has more about facial expressions.