The effect of eyelash length on attractiveness: A previously uninvestigated indicator of beauty.

Abstract

Human eyelashes are one of the facial features that contributes to facial attractiveness. While enhancing the appearance of eyelashes has been practiced since antiquity, research investigations that consider the effect of their length on perceived attractiveness are scarce. Length of eyelashes can be an indicator of health, and it has recently been proposed that there is an optimum length for eye protection. In the current article, we investigated if the attractiveness of eyelash length dovetails with these evolutionary and functional proposals. Our results support this proposition, with the preference for eyelash length following an inverted-U function, with the highest ratings peaking at approximately one third of the eyes' width. Interestingly, there is a difference between male and female faces, suggesting that while in general, eyelashes of an optimum ratio are considered more attractive, this preference is not solely a biologically adaptive phenomenon and is influenced by cultural norms. Public Significance StatementEyelashes have evolved to protect eyes from external contaminations and excessive evaporations, and changes in eyelash length can reflect different congenitally and noncongenitally diseases. From this evolutionary and biological perspective, we test and confirm that the perceived attractiveness of eyelashes dovetails with their predicted value to protect the eyes and signal healthiness to others. Contrary to some beliefs that the attractiveness is increasing with the length of eyelashes on female faces, the preference for eyelash length follows an inverted-U function. This function is observed for both female and male faces.

Eyelash length attractiveness across ethnicities

“…These studies have shown that facial features might be regarded differently and preferred by one's own-ethnicity compared to other ethnicities 10 , 17 . Therefore, the findings by Pazhoohi and Kingstone 1 might not generalize across different ethnicities. In other words, it is crucial to examine whether the previous finding with an inverted-U pattern 1 will be generalized and observed across diverse ethnicities.…”

“…Pazhoohi and Kingstone 1 introduced the possibility that the perception of eyelash length attractiveness might dovetail with the proposed phylogenetically adaptive functionality of eyelash length 2 . Specifically, arguing from an adaptive evolutionary perspective that attractiveness is an honest signal of health and genetic quality 3 , 4 , Pazhoohi and Kingstone 1 proposed that eyelash length should be perceived as most attractive at the length where: (a) it has the highest functionality in minimizing evaporation and contamination at the ocular surface 2 , and (b) it is associated with the highest health condition of the eyelashes 5 , 6 .…”

“…From a health and genetic point of view, previous research has shown that long eyelashes 6 , 7 and short eyelashes 5 , 8 can serve as indicators of congenital and noncongenital diseases. Accordingly, Pazhoohi and Kingstone 1 hypothesized that face attractiveness would show an inverted-U relationship with the eyelash/eye L/W ratio; with the highest attractiveness arising around the 0.35 L/W ratio. Participants were asked to rank the attractiveness of both a man's face and a woman's face.…”

“…Also, while very short or no eyelashes were ranked as least attractive for women faces, very long eyelashes were ranked as the least appealing for men faces. This discrepancy in eyelash preference between male and female faces was attributed to factors such as cultural norms 1 .…”

To Enhance, or not to Enhance: The Situational Context Shapes Women's Intentions on Amount and Diligence of Makeup Application

“…Eyeliner can also make the eyes appear larger ( Matsushita et al, 2015 ) and create the appearance of a whiter sclera, which can enhance perceptions of attractiveness ( Provine et al, 2013 ). Similarly, long eyelashes, which men find attractive ( Pazhoohi & Kingston, 2020 ), can be modified with mascara or eyelash conditioners and serums. The underlying assumption for these effects is that women exaggerate facial features that have been shaped by sexual selection to advertise aspects of their physical condition ( Batres et al, 2018 ; Davis & Arnocky, 2020 ; Jones & Kramer, 2015 ).…”