Research published in scientific report We found that straight women reported feeling more jealousy when they imagined a more feminine-looking woman flirting with their romantic partner. Although this pattern was present among lesbian participants, the strength of the association was significantly weaker.
Facial femininity is the degree to which a person’s facial features exhibit characteristics typically associated with female faces. These features include larger eyes, fuller lips, a smaller chin and chin, higher eyebrows, and smoother facial contours. Facial femininity is influenced by biological factors such as sex hormones, especially estrogen, during development.
Researchers most often study facial femininity in the context of evolutionary psychology and social cognition. In general, women with feminine faces tend to be perceived as more attractive, more youthful, and healthier. Research has also shown that facial femininity can influence social judgment, with women with feminine faces more likely to be perceived as warmer, kinder, and more trustworthy.
Study author Junzhi Dong and his colleagues point out that evolutionary theory suggests that individuals who exhibit signs of higher “mate value” (e.g., those who are more physically attractive) represent a greater threat to the romantic relationship and, as a result, cause greater jealousy.
Previous studies have shown that female rivals elicit higher levels of jealousy, but those older studies often relied on computer-manipulated facial images or forced-choice tasks. Critics argue that this method lacks “ecological validity” because it doesn’t reflect how real, unedited people are viewed in the real world. With this in mind, researchers conducted a new study to see if the jealousy effect holds true when women view unretouched, natural photos of potential rivals.
Study participants included 51 heterosexual women and 49 lesbian women from the UK, with an average age of 28 to 29 years. They were shown 50 natural photos of Caucasian women’s faces with androgynous expressions and asked, “Imagine this person flirting with your romantic partner (if you don’t currently have a romantic partner, imagine you have one). How jealous would you be?” Women responded on a scale of 1 to 7, ranging from “not very jealous” to “very jealous.”
To ensure accuracy, the study authors used two different methods to determine how feminine the 50 faces actually were. First, we used statistical software (facefuns package in R) to map facial landmarks to create a purely objective, mathematical measure of facial shape femininity. Next, another group of 30 straight and 30 lesbian women were asked to rate the subjective femininity of their faces.
Both measurements gave the same results. When straight women imagined a more feminine woman flirting with a romantic partner, their jealousy increased significantly. This same pattern was observed among lesbian women, but the strength of the association was weaker.
The researchers suggest that this weak correlation may reflect the fact that lesbian dating is characterized by more diverse attractiveness preferences (such as the butch/femme dynamic), whereas straight men are more universally attracted to more feminine female characteristics, making rivalry for straight women a more uniform threat to straight women.
“Taken together, these results provide further evidence that the femininity of a potential rival’s face influences reported jealousy, particularly in heterosexual women, and are further evidence for the proposal that putative markers of a rival’s mate value play a role in women’s jealousy,” the study authors concluded.
This study confirms that previous findings regarding facial femininity and jealousy are not simply a byproduct of manipulated photos. However, this study has limitations. The experiment was conducted on a relatively small group of English-speaking women in the UK, and all 50 photographs used in the experiment featured white women. Additionally, bisexual and pansexual women were excluded. The authors note that findings in other cultures, different sexual orientations, or more diverse image sets may yield different results.
The paper, “Femininity of a Potential Rival’s Face Predicts Jealousy in Both Heterosexual and Lesbian Women,” was authored by Junzhi Dong, Benedict C. Jones, Esperanza Miyake, and Victor KM Hakusui.
