Have you ever wondered why hair comes in different types, from curls (and its variants) to wavy hair to straight hair? Could curls have some kind of evolutionary advantage?

Opinions may differ on the why, but now research tells us that it might all be linked to the process of adapting to the not-so-flattering climatic conditions that characterize the “original” home of the human species—the torrid African savanna.

Curls, are praised for their resilience, and with research now linking them to a speculative process of evolution, our curiosity got us reading and writing. Join us as we take a sneak peek at claims that curly hair might have advantaged the early humans as summarized below:

• Curls act as a natural shield against the sun, providing protection against the scorching rays.
• The presence of curls is proposed to have played a role in enhancing brain growth among early humans.
• Curls are theorized to have served as a natural insulation, offering protection against radiation
• The unique structure of curly hair is suggested to be beneficial for retaining moisture, a crucial factor in challenging environments
• Beyond their functional advantages, curly hair is contemplated as a potential medium for social signaling among early human communities.

Having shared briefly the reasons for such seemingly bold claims, how about sampling one of the more recent studies on the subject? After all, isn’t science about evidence?

A study examining the DNA of 6,357 people from Latin America, considered a genetic melting pot, showed differences in hair type among races. The conclusion was that hair type is a factor of migration and evolution, with the gene, PRSS53, affecting the curliness of hair. [1]

Now let’s take a detailed look at the reasons (speculative of course) why curly hair is an evolutionary advantage.

Is Curly Hair an Evolutionary Advantage?

1. Protection against the sun

You will agree that this reason sounds intuitively obvious, more so if you always have to contend with an afternoon blaze that characterizes the tropics and is obviously worse in the equatorial regions of Africa where evolutionists imagine the earliest humans originated. That beautiful mass of tight curls is a perfect natural canopy for the scalp.

2. Boosting brain growth

Research shows that the brain-curly hair connection begins at the point where the change from Homo erectus (man’s straight-walking direct ancestor) to the Homo sapiens (the current person) made it necessary to develop a larger brain.

The fact that the brain is highly sensitive to heat meant that curly hair provided just the perfect environment for it to thrive. The adaptation and survival of species called for a heat-regulated environment that curly type of hair provided—it offered a protective environment for the equally evolving brain to thrive.

As a heat protective mechanism, curls increase the hair volume and the space from the scalp to the top of the hair, insulating the brain from radiation while at the same encouraging heat loss.

3. Insulation against radiation

Curly hair, science suggests, protects the hair against the sun’s damaging rays much better than any other.

 At the same time, the airspaces between the curls allow the loss of heat to the atmosphere. It is all simple up to this point, until research suggests a link with the demands of survival in the past in faraway Africa.

The dry sunny climate, and the high temperatures of the African savanna, the study says, prompted the curling of hair strands as a coping mechanism. That is the evolutionary twist in which this trait might have evolved in early humans in equatorial Africa where the sun is overhead for much of the day throughout the year, with the straighter hair emerging as some humans migrated into cooler areas.

4. Moisture retention

Researchers at Penn State University studied hair and heat transfer from the body to the atmosphere under no hair, straight hair, moderately and tightly curled hair. [2]

They found that tightly curled hair minimized the need to sweat to stay cool and helped to conserve water and avoid dehydration—this hair condition performed better than the straight and moderately curly hair, suggesting that it was an advantage to the growth of human brains.

The tightly curled hair also minimized the need to sweat to stay cool, which would help conserve water and avoid dehydration

5. Social signaling

Used to identify a race, curly hair has had connections to the African race and come to be referred to by such terms as African hair or afro-textured hair denoting African ancestry.

Opponents of social signaling, however, are uncomfortable with the classification for not accounting to intra-racial differences that exist among core race-classified hair types, e.g., the existence of East Asian and West Asian hair. [3]

These classifications can be flawed because it is not unusual to find European/Caucasian or Asian hair that is curly.

Yet, amidst the existence of labels like African hair or Afro-textured hair, we encourage a shift in perspective. Can we not find pride in the curls so labeled? Instead, let’s invite you to relish the beautiful chaos, as someone wisely expressed. Contrary to the notion of African hair being associated solely with stiffness and tensile strength, there’s substantial evidence suggesting its high lipid content contributes to resilience against certain external stressors. [4]

But there is some disagreement on this, with one study reaching a different conclusion.

That particular study puts Asian hair at a higher lipid composition than either European or African hair. Such a conflict could be because it can be complex measuring lipids in the hair. Still, it provides an important talking point from which to re-consider the racial prejudices that may paint curly (African or Afro-textured) hair as perhaps less beautiful than the others. 

Now we can tell you to love your curls and they will love you right back, won’t they? Or you could simply remember the next time you feel a dip in your confidence because of the frizz: “Frizz happens but curls conquer.”

A Scholar’s Take on The Advantages of Curly Hair

Meanwhile, this perspective by Professor Tina Lasisi of the University of Michigan in Ann Arbor might also interest you. See her podcast interview below:

If the good Professor is not thinking that “we’re the only weirdoes that are naked except for our head,” [5] she is busy telling you to love your curls, and we believe she is right. What about you? Your and her reasons could be worlds apart (whose are weirder?) but the perspective is worth the attention.

Anyway, in summary: Is curly hair an evolutionary advantage?

Science is pointing to curly hair as adaptive heritage, an evolutionary advantage. From protecting the scalp against the sun to insulation against radiation to retaining the moisture to social signaling there is always something to jog our minds every time we feel or see the curls.

Therefore, that Afro-textured gift on your head is a wonderful delight that is as good as you treat it or pamper it. With that, we don’t discount curly hair enthusiasts latching onto this adaptive trait narrative, no doubt a welcome shot of ego boost and confidence.