Men with blue or green eyes exhibit a tendency to prefer women who also have lighter colored eyes, according to published in the Archives of Sexual Behavior. Additionally, the findings indicate that light-eyed men tend to be more concerned about other light-eyed men being potential romantic rivals.
Men face the issue of paternity uncertainty, which refers to men being uncertain whether they are the biological father of their children or if another man is. To help solve this problem, men can adjust the level of investment in their partner’s children. Men tend to invest less in their children when paternity confidence is low.
Men use physical resemblance as an indicator of genetic relatedness. By choosing a mate who has the same recessive traits as them, men can increase their paternity confidence. Eye color, which is a highly heritable trait, may influence men’s mate preference and affect male jealousy. Light-colored eyes (blue and green) are a recessive trait, in which it would be unlikely for a child to have brown eyes when both parents have blue eyes.
Researcher Paola Bressan studied 1,237 Italian men who identify as heterosexual or bisexual and prefer female partners. 432 of the participants had either blue or green (light-colored) eyes, 805 of the participants had either brown or dark brown (dark-colored) eyes, and 621 of all participants reported currently having a romantic partner.
Participants were shown 10 images (via professional photo-retouching software PortraitPro) of an attractive young European woman with different eye colors. Half of the participants were shown images of blue/dark brown eyes and the other half of participants were shown brown/green eyes.
Participants indicated which female they would choose for a long-term and short-term relationship and how attractive the woman is. Participants were also shown images of 8 identical attractive male faces with the only difference being eye color (light vs dark). Participants reported which face they would be jealous of if they suspected their partner cheated on them.
Results of this study show that the light-eyed woman was more attractive to men than dark-eyed woman. Specifically, light-eyed men chose the light-eyed woman 66% of the time and dark-eyed men chose the light-eyed woman 58% of the time. Regarding rival men, light-eyed men were chosen as threatening 66% of the time by light-eyed men and 56% of the time by dark-eyed men.
Based on the results, Bressan suggests that light-eyed women are preferred by men (especially by light-eyed men) and are rated as more attractive when the man is seeking a long-term relationship. This finding suggests that men are more willing to invest in a woman who has the same recessive eye color as him because he is more certain of his paternity when the child also has light-colored eyes. Light-eyed men may be more jealous/threatened by light-eyed men because the man cannot differentiate which man’s genes gave the child blue eyes, thus decreasing paternity confidence.
A limitation of this study is that only men were studied, but women also likely have a preference for light-eyed men. Some challenge the validity of the implications regarding parental investment considering European babies’ eyes are initially blue, regardless of the parent’s eye color. However, research shows that parental investment increases slowly after childbirth when the baby’s eyes resemble their true color.
The study, “Blue Eyes Help Men Reduce the Cost of Cuckoldry“, was published September 27, 2021.