People interpret long eyelashes as a signal of openness to casual relationships

A study conducted in the United Kingdom found that people perceive eyelashes that are about one-third the width of the eye as the most attractive and healthiest. Both shorter and longer eyelashes were rated less favorably. However, participants also interpreted longer-than-optimal eyelashes as a signal of sexual receptivity—that is, individuals with longer eyelashes were perceived as more open to casual relationships. The findings were published in the Archives of Sexual Behavior.

Eyelashes play an important role in shaping how people perceive attractiveness and health. As a subtle facial feature that frames the eyes—an important focal point in social interaction—eyelash length can influence impressions in unconscious ways. Previous research shows that moderately long eyelashes are viewed as the most attractive, likely because they enhance the eye’s appearance without appearing artificial or exaggerated.

Very short eyelashes may be associated with poor health or aging, while extremely long or obviously artificial lashes can appear unnatural or even unhealthy. From an evolutionary standpoint, eyelashes help protect the eyes from dust, light, and airflow, so their appearance may serve as an indirect cue of good ocular health. Symmetrical lashes that frame the eyes tend to be linked with facial harmony and beauty. In women, longer lashes are often associated with femininity, youthfulness, and reproductive fitness, while in men, shorter but still noticeable eyelashes contribute to a balanced and healthy appearance.

Study author Farid Pazhoohi aimed to investigate whether perceptions of health and attractiveness based on eyelash length align—and whether long eyelashes could also serve as a signal of sexual receptivity. He noted that while people tend to prefer a moderate eyelash length for attractiveness, cosmetic trends such as eyelash extensions remain popular, potentially reflecting other social signaling motives. Based on this, he hypothesized that although very long lashes might be seen as less attractive, they could be perceived as signaling sexual openness or availability.

The study involved 120 participants residing in the U.K., recruited via Prolific. Seventy-seven were men, and the average age of participants was 32 years.

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To test his hypotheses, Pazhoohi used Daz3D software to create computer-generated images of female faces representing four ethnic groups: Asian, Black, Indian, and White. For each ethnic group, he produced 11 variations of each face that differed only in eyelash length, ranging from none to half the width of the eye. Participants were shown these faces and asked to rate how healthy, attractive, and sexually receptive they perceived each woman to be.

The results confirmed that perceptions of both health and attractiveness followed an inverted-U pattern, peaking when the eyelash-to-eye-width ratio was around 0.33—approximately one-third. Both shorter and longer eyelashes were associated with lower ratings of health and attractiveness. This pattern was consistent across all ethnicities and regardless of the participant’s sex.

However, perceptions of sexual receptivity followed a different trend. Faces with longer eyelashes were rated as more sexually receptive, even when those same eyelashes were rated as less attractive or healthy. In other words, very long eyelashes were interpreted as a possible signal of openness to short-term or casual relationships.

“Results showed that eyelash length is positively associated with perceived sexual receptivity, suggesting that longer eyelashes might signal openness to casual relationships, despite lower attractiveness and health ratings at lengths beyond the optimal one-third ratio. This indicates a potential reproductive strategy linked to wearing long eyelashes and reveals that perceptions of attractiveness and sexual receptivity can diverge,” Pazhoohi concluded.

The study sheds light on the way people interpret eyelash length. However, it should be noted that the study focused exclusively on the perception of female faces. Perceptions of eyelashes in male faces might be different. Also, the faces participants evaluated were static illustrations primarily differing in skin color and eyelash length. This differs from how people evaluate psychological characteristics of others in real-world situations.

The paper, “Long Lashes, Mixed Signals: Investigating the Effect of Eyelash Length on Perceived Health, Attractiveness, and Sexual Receptivity,” was authored by Farid Pazhoohi.