A recent article entitled “Sex Differences in Sports Interest and Motivation: An Evolutionary Perspective” argues that men and women have evolved different motivations for sports. The authors suggest that these evolved differences have 2 important implications. 

1) Boys and girls are naturally drawn to different kinds of sports, so these sex differences should be included in designing physical health studies and public health programs.

2) Because of these natural differences between males and females, equal opportunity mandated by Title IX (the law that prohibits sexual discrimination in educational opportunities, including sports) may lead to suboptimal allocation of resources and possibly discrimination against males.

Are they right? Is Title IX against human nature? No, it’s not that simple.

Males and females do differ in key biological factors. One area where we see clear and consistent sex differences is body size and upper body strength.  When looking at behaviors where size and upper body strength are central to performance, there will be, on average, substantial differences between the sexes. Competitive physical sports such as American football, baseball, basketball, wrestling and boxing are areas where we’d expect to see such differences. 

There are going to be many more males who could fill the physical requirements of being a nose tackle or a heavy weight boxer than there are females. In such cases, it is not surprising that males are more interested in those sports than females. But the paper’s authors are making a different kind of claim.  They suggest that it’s more than just physical requirements compelling these preferences. They attribute evolved sex differences for these distinct motivations.

They conclude that sometimes both males and females do engage in sports for similar reasons, such as to develop allies and coalitions and to develop particular types of skills. But that more often females prefer sports that enable them to emphasize their ability to engage in courtship displays, whereas males are largely interested in sports that enable them to compete for “status, to “show off” their physical qualities, and to evaluate the abilities of other males. The authors do note that “socialization” processes play some role, but argue that the core patterns emerge from different evolutionary pressures on males and females and are mediated (enabled) via substantially different prenatal hormonal exposures.

It may seem like a nice, neat way to explain boys and girls, but real life is not that simple.   

Of course, humans are heavily influenced by our evolutionary histories and by the patterns of prenatal hormones we are exposed to.  However, the question here is whether or not we can connect the reported patterns of male and female differential investment in specific sports to specific patterns and processes in evolutionary histories. For example, is showing off in a physical sport akin to being a strong hunter in the evolutionary past? Do either of these things connect with fitness benefits or heritable traits?  In many societies when the best hunters return to the village, they share their kill with many…often ending up with a smaller share for themselves and their family.  The soccer star being paid 20 million Euros rarely returns to his hometown and shares all of his wealth with the townsfolk. Subsistence hunting and playing sports are not comparable contexts or roles.

Genetic and developmental influences on size, muscle density, and hand-eye coordination are complex and contingent on local ecologies. It’s highly unlikely that the range of activities lumped into the category “sports” provide venues where patterns of showing off, courtship displays and assessing competition could transfer to actual evolutionary fitness (reproductive success).  Being a better athlete does not necessarily lead one to more offspring than other roles or jobs in society. Yes, modern day elite athletes might get more sexual opportunities than, say, bank tellers or electricians (this is not quantitatively tested, just assumed by many), but being an “elite athlete” is not an evolutionary trait that can be inherited or selected for, it is a social role (and a super rare one).

Making direct comparisons between patterns of human participation in complex contemporary social realities—like sports, jobs, or political systems—and specific patterns of natural selection in the human past is a dubious endeavor.  A pattern where males invest more in certain types of sports than girls do does not automatically reflect evolutionary outcomes any more than the fact that most bankers, politicians, and airline pilots are male does. Men are not “evolved” to be better bankers, politicians and pilots. But due to a range of complex histories, ecologies, and societal contexts, they are the most likely to full those positions currently.

But patterns of gender differences are changing. Why? Because Title IX and similar programs offer enhanced opportunity for females to have access, from early on, to the formative and developmental processes that can interface with our bodies, minds and physiologies. We don’t know what the evolutionary limitations on gender equality and patterns are…we rarely offer females the chance to show us. 

Humans are never outside of social, ecological and historical systems that structure development of our physiology and neurobiology in addition to our behavior. In such systems, scientific understanding of patterns of behavioral differences between of men and women have to include assessment and integration of biological, historical, social and cultural factors simultaneously. They all mutually shape one another, so trying to identify biological sex differences as the underlying driver of complex behavioral processes is much too simplistic an approach.  

Title IX is not anti-evolutionary. Title IX is a reaction to a stacked deck, a history of restrictions and lack of access for females. If we really want to see patterns of evolved differences in males and females, we need to control for the massive bias in access and exposure. For sports, Title IX, by setting a relatively equal playing field early on in development, might actually offer us a better evolutionary experiment.  Title IX offers us the chance to be humans as well as male and female. 
 

You are reading

Busting Myths About Human Nature

Revisiting the Google Manifesto

Scientists cannot allow the ignorant and erroneous misuse of “biology”

Get the Science Right!

What popular books get wrong about human evolution.

Hassles Are Part of Being Human, Even for Our Ancestors

It’s never easy being human, or even almost human, but that hasn’t stopped us.