What Can a Man’s Finger Size Tell You About His Sex Appeal?

New research claims that a man’s finger size predicts who his partner will be.

Posted Feb 10, 2018

In the complex prediction equation you may use to determine which men appeal to which women, researchers have suggested that you consider such factors as his height, intelligence, wealth, and status. Recently, researchers claim that women want tall men, men with new and large cars, and high intelligence. Underlying the assumptions of these studies is theory based on evolutionary psychology that what’s important about a man’s attractiveness to women is his mating potential. A new study by Berenika Kuna and Andrej Galbarczyk (2018) of the Jagiellonian University Medical College in Poland adds now to the claim not only that it’s possible to predict a man’s appeal as a mate to women from an easily observed physical attribute, but also the mating potential of the women drawn to have a relationship with him.

The physical attribute the Polish researchers focused on was a man’s finger length, bringing back to mind the claim by then-candidate Donald Trump that his small hands had no relationship to his own mating potential. In this particular study, however, it wasn’t just the size of a man’s hands in an absolute sense, but the relative size of his second finger to his fourth that was of interest. The measure that Kuna and Galbarczyk used, then, was the 2D:4D ratio, so that men with lower scores had relatively longer fourth finger length.  

This longer ring finger ratio, in turn, the Jagiellonian College researchers predicted, would allow men to attract women who themselves were more desirable mating partners. Their measuring tapes in hand, Kuna and Galbarcyzk decided the best way to define an attractive female partner was to calculate the waist-to-hip ratio. Attractive women, in this framework, have smaller waists relative to their hip sizes. Women with wider hips, in the evolutionary perspective of the authors, are better at producing children, and their narrower waists serve to accentuate this feature of their bodies. Not stopping below the waist, the research team also decided to use breast size as well. In their words, “In Western cultures, female attractiveness assessment includes mainly waist and breast size as cues of youthfulness, health status, and reproductive capability” (p. 8). Hormonally advantaged, such potential mates are more fertile and therefore better prepared to help propagate the species.

If at this point you’re trying to imagine why mating potential is relevant in modern society, keep in mind that the evolutionary perspective looks solely at biology in determining who’s attracted to whom. Evolutionary theories regard the contemporary world’s definition of attractiveness as stemming from our primitive inheritance in which all that matters is having babies. A contrary biosocial view would argue that whatever hormonal advantages may have existed hundreds of thousands of years ago are not as relevant as the definition that the prominent culture imposes on norms for attractiveness. Moreover, by defining women’s and men’s attractiveness in terms of their biological imperatives, we continue to maintain stereotypical views of women as child-bearers and men as the breadwinners who care for the families that need their support.

Returning now to the data presented by the Polish authors, and with the idea that there are alternative ways to approach their research question, let’s see who was in the study and how “attraction” was defined. The participants consisted of 50 heterosexual couples with an average age of 24 years for men and 22 for women. We don’t know how this sample was obtained, nor what was the minimum amount of time the couples had been together. None of the women were taking hormonal forms of birth control. On average, they had been together for a little over two years, but some had been seeing each other for only a few months. The men’s finger size ratios fell in a relatively narrow range from just under to just over 1. For the women, the measurements of waist, hips, and breasts produced two categories of “women with relatively narrow waists and large breasts,” and “other body types” (p. 9), although the authors also used the actual measurements in some analyses. There were no measures of relationship satisfaction and, indeed, length of time together was controlled for statistically.

One of the findings, according to the Polish researchers, supported the study’s hypotheses. Using the right hand only, the lower 2D:4D men’s partners had a lower waist-to-hip ratio. There was only a slight difference for the left hand, and no effects for breast size. Thus, the entire study rested on a small, but significant, relationship between a man’s longer right ring finger relative to the index finger and a woman’s smaller waist.

The authors regard the effect of finger size as supporting the importance of testosterone as a determinant of a man’s mating potential which, in turn, allows him to attract the more reproductively advantaged female. That longer ring finger represents, in their view, the impact of the intrauterine environment that allowed these fingers to grow longer in the presence of more testosterone. From this, Kuna and Galbarczyk conclude that, “Our findings show a long-lasting impact of the prenatal hormonal environment in a real mating context,” supported by the fact that the couples were not just hooking up, but in real “long-term relationships.”

Before you rush out to get your own ruler to judge who to get into a relationship with—or, if you’re a man, you try doing some stretching exercises on your right ring finger—it may be worth keeping the study’s limitations in mind. Notably, the couples were relatively young, their relationships were just about two years at their max, or perhaps as many as four, and inexplicably, the women weren’t taking birth control. Furthermore, that old “correlation does not equal causation” theme should be playing in your head. Is it possible, rather than the longer-fingered men deciding that they need “fertile” women, it’s the shapely women who scope out the scene for more attractive men? As the authors point out, the finger length ratio also relates to some even more visible features of men, such as their facial symmetry, height, and “masculine” appearance. Women defined by society as more attractive due to their body shape may be the ones making the decisions of who they should date, not the other way around.

Consider, too, the fact that these couples were relatively young. They may be at an age where the dating game places importance on physical appearance. As you mature into your 20s and beyond, you learn that a good partner isn’t always the one who society decides is “beautiful,” or even sexy.

In sum, to find the person who will be the best for you in the long term, you can put the yardstick away and instead, explore those inner qualities that will maintain your actual relationship fulfillment.


Kuna, B., & Galbarczyk, A. (2018). Men with more masculine digit ratios are partnered with more attractive women. Personality and Individual Differences, 1248-11. doi:10.1016/j.paid.2017.11.040.