An experiment published in Evolutionary Behavioral Sciences suggests that the most attractive eyelash length is about one-third of the width of the eye. Interestingly, participants ranked the most attractive eyelash length differently for male and females faces, suggesting the interference of a cultural gender norm.
Since ancient times, people have engaged in eyelash-enhancing practices as a way of modifying their attractiveness. While some researchers have suggested that eyelashes are perceived as more attractive the longer they are, long eyelashes can also signal disease, such as immunodeficiency. From an evolutionary perspective, the ideal eyelash length to signal healthiness and, therefore, attractiveness should be somewhere in between long and short.
As research on this topic is scarce, study authors Farid Pazhoohi and Alan Kingstone set out to systematically investigate the influence of eyelash length on perceived attractiveness.
Pazhoohi and Kingstone asked a sample of 132 college students to rank a series of images of faces in order of attractiveness. Each subject was shown 11 images of the same face, identical except for the eyelash to eye-width ratios, which varied by increments of .10 units. In order to explore the influencing effect of gender, some of the students saw male faces and some of the students saw female faces.
The results showed that the link between eyelash length and attractiveness followed an inverted U-function, with “the highest ratings peaking at approximately one third of the eyes’ width.” In other words, both faces with very long eyelashes and those with very short eyelashes were rated as less attractive. This finding is consistent with the evolutionary perspective, given that both very long and very short eyelashes can signal disorder or disease.
However, subjects’ preferred eyelash length differed when rating male and female faces, suggesting the phenomenon has more than just a biological basis. Specifically, female faces were rated the least attractive when eyelashes were very short or nonexistent, whereas male faces were rated the least attractive when eyelashes were very long. In other words, participants preferred slightly longer eyelashes on women and shorter on men, suggesting that gender norms played an interfering role.
The overall findings suggest that there is an optimum length at which eyelashes are perceived to be most attractive, which has an evolutionarily adaptive basis. Still, this preference can be swayed by cultural gender norms. As the researchers speculate, cultures in which it is more accepted for men to wear eye-enhancing makeup might present with different findings than the current study.
The authors suggest that future studies should include faces of different ethnicities as well as 3D images to further extend their research.
The study, “The effect of eyelash length on attractiveness: A previously uninvestigated indicator of beauty”, was authored by Farid Pazhoohi and Alan Kingstone.