"Odor pleasantness and facial attractiveness integrate into one joint emotional evaluation," study author Janina Seubert, a cognitive neuroscientist and former postdoctoral fellow at Monell Chemical Senses Center in Philadelphia, said in a Monell news release. "This may indicate a common site of neural processing in the brain."
The study, published online recently in PLOS ONE, involved 18 young adults. Of these, two-thirds were female. The participants were shown photographs of eight women and asked to rate their attractiveness. They were also asked to determine the ages of the women in the photos.
As the participants viewed the photographs, one of five different smells was released. The odors, which included a blend of fish oil and rose oil, ranged from unpleasant to pleasant. The participants were also told to rate the pleasantness of the odor they smelled.
The study showed that the pleasantness of the odor had a direct influence on the attractiveness ratings of the women in the photographs. Meanwhile, visual age cues, such as wrinkles, were linked to the perception of older age. The odors, however, also played a role.
Pleasant smells enhanced visual age cues, the researchers found. So, older faces appeared to be older and younger faces seemed younger. Unpleasant odors on the other hand, weakened this effect. As a result, younger and older faces appeared to be closer in age.
"These findings have fascinating implications in terms of how pleasant smells may help enhance natural appearance within social settings," study co-author Jean-Marc Dessirier, lead scientist at Unilever, said in the news release. "The next step will be to see if the findings extend to evaluation of male facial attractiveness."
The U.S. National Institute of Neurological Disorders and Stroke has more about the human brain and how it works.