Tuesday, December 05, 2023

The Evidence for Women and Men as (Persistent) Hunters


A Famous Photograph of the Ultrarunner Sophie Power in 2018, Who Was Running the 105-mile Ultra-Trail du Mont-Blanc Race in the Alps, While Breastfeeding Her Child at Rest Stations

One of the best arguments of Cara Ocobock and Sarah Lacy for "Woman the Hunter" is that the physiology of women's bodies and brains gives them an endurance activity advantage over men, and this would have made Early Stone Age women good as persistent hunters who chased their prey over long distances.  But because of Ocobock and Lacy's false view of the "Man the Hunter" theory as denying women's participation in hunting, they mistakenly criticize the proponents of the persistence hunting hypothesis for assuming that only men engaged in persistence hunting.  They thus fail to see how recognizing that men have predominated in hunting that requires endurance running is compatible with recognizing that women in foraging societies have often engaged in endurance running in hunting and scavenging for food.

The most important proponents of the persistence hunting hypothesis have been Daniel Lieberman, Dennis Bramble, and Louis Liebenberg (Bramble and Lieberman 2004; Liebenberg 2006).  The idea was first suggested by David Carrier (1984).  The best short summary of the reasoning is Lieberman and Bramble's "The Evolution of Marathon Running" (2007).  I first wrote about this in an essay six years ago.  Some critics have dismissed the endurance running hypothesis as implausible (Pickering and Bunn 2007).  Lieberman and his colleagues (2007) and Liebenberg (2008) have replied to these critics.

The reasoning begins with the observation that humans are unique among primates in their capacity for endurance running, defined as the ability to run at a high speed over long distances (over three miles) using aerobic metabolism.  Chimpanzees can only rarely sprint for short distances, and they never run marathon-length distances.  While most mammals good at running can out-sprint humans, humans can outrun most of them over long distances.  Sometimes they can even outrun horses in hot weather.

This raises the questions of how, when, and why this uniquely human capacity for running long distances evolved.

How?  The mass-spring mechanics of human running depends on storing spring-like energy in the tendons and ligaments of the legs and feet.  The largest tendon in the body is the Achilles tendon, which connects the calf muscles to the heel bone.  The non-human African apes do not have a well-developed Achilles tendon.  Humans also have long legs relative to body mass, more compact feet, and relatively short toes.  These and other bodily traits provide the energetic needs of human running.

There is also a need to stabilize the body's center of mass during running.  The trunk and neck of human runners are forwardly inclined in running, which creates a tendency to pitch forward.  The human body has many features that help to stabilize the trunk, including a greatly enlarged gluteus maximus.  This is the single largest muscle in the body and one of the most distinctive features of the human body--our big butts.

The greatest physiological challenge for runners is heat.  Running generates as much as ten times more internal heat in the body than walking.  Runners must cool down to avoid hyperthermia.  Most mammals cannot run over long distances without suffering hyperthermia, particularly in hot weather.  Humans are unique in their ability to run long distances in hot weather, because of their many eccrine sweat glands and reduced body hair that allow for dissipating heat more effectively than other mammals who cool the body by panting.  This reliance on sweating for thermoregulation does, however, create the problem of high water and salt demands for human runners.

When?  The fossil evidence for the first emergence of endurance running in our hominid ancestors is hard to interpret.  But Lieberman and his colleagues believe that this likely arose first about 2 million years ago with Homo erectus, because most of the structural bases of endurance running in the skeleton are present in early H. erectus.

Why? Archaeological and ethnographic evidence suggests that endurance running evolved when our early hominid ancestors became carnivorous hunters and scavengers without sophisticated projectile weaponry. As I have indicated in some previous posts, stone-tipped spears appeared first about 200,000 years ago, and the bow and arrow arose not much earlier than 50,000 years ago.

The first hunters probably had no weapons better than stones and untipped spears.  They could have scavenged carcasses left by lions, but to do this, they would have had to run to the carcasses before hyenas arrived.  It is hard (and dangerous) to kill large animals with a spear.  But in hot weather, human hunters could have persistently chased their prey until the animal was driven to hyperthermia, and then it could be safely killed at close range.

Ethnographic studies of hunter-gatherer societies in the modern world have few reports of persistence hunting, because recent foragers have not needed to rely on this hunting strategy.  Hunting with projectile weapons, hunting dogs, and other hunting tools works better.  And yet, persistent hunting has been documented for the Kalahari Bushmen, the Tarahumara of northern Mexico, the Navajo and Paiutes of the American Southwest, and the Australian Aborigines (Lieberman et al. 2007; Lieberman et al. 2009; Lieberman et al. 2020).  There is a good YouTube video of persistence hunting in the Kalahari.

Woman the Persistent Hunter?  Even if we are persuaded by Ocobock and Lacy's claim that women in foraging society hunted, we might assume that it would have been hard for women to engage in persistence hunting, particularly when they were encumbered by caring for young children.  But that picture of Sophie Power breastfeeding her three-month-old child while running a 105-mile race in the Alps is for Ocobock and Lacy a vivid refutation of that assumption.  Yes, of course, she needed some help from her husband, who transported the child between rest stations.  But we know that women in foraging societies have generally relied on "alloparenting" (relatives and friends helping women with their childcare), and so this could have allowed them to run down prey over long distances.

Ocobock and Lacy concede that men do have a "power activity advantage" that would have made them good hunters--the advantage that comes from high testosterone that increases muscle growth, more type II ("fast-twitch") fibers, a larger heart and lungs, a greater number of red blood cells for carrying oxygen, and increased glycogen utilization.

But, on the other hand, they stress the "endurance activity advantage" of women over men, because women have more type-I ("slow-twitch") fibers that increase endurance, greater fat stores that aid endurance, and higher estrogen levels that enhance athletic performance in various ways (Ocobock and Lacy 2023a).

Until recently, female ultra-racers like Sophie Powers have finished with slower times than the fastest men.  But now the women are sometimes winning these ultramarathon races.  In 2019, Jasmine Paris had the overall winning time for the 268-mile Spine Race through England and Scotland.  Perhaps this shows what their Early Stone Age female ancestors could do.

Ocobock and Lacy (2023b) complain that the proponents of the persistence hunting hypothesis assume that such hunting was exclusively male:
"Bramble and Lieberman's (2004) introduction to the persistence hunting hypothesis never mentions sex, so it is not clear whether values given related to human endurance running are averages of both sexes or are exclusively male.  They describe the Homo form in contrast to Australopithecus in what could be interpreted to be male or masculine terms, e.g., 'tall, narrow body form,' 'low, wide shoulders,' 'narrow pelvis' (348) along with masculine figures, as if it were obvious that the endurance runners of human evolution were male, and it need not be explicitly stated.  A discussion of sex and female endurance capabilities would actually further their argument if it were acknowledged and included rather than defaulting to males alone" (3).

Ocobock and Lacy are mistaken about this.  They ignore the many places in Lieberman's writing where he explicitly indicates that women have sometimes engaged in persistence hunting, and that they are as capable of endurance running as men are.  For example, in his book Exercised (2021), he writes: "These traditions remind us that running was never just for men.  If you attend any major race today, women comprise half the runners, thanks to pioneers like Bobbi Gibb and Katherine Switzer.  Although men do most hunting in hunter-gatherer societies, women also sometimes persistence hunted, and they ran races both sacred and secular" (213).  He has also quoted from Nisa, a San hunter-gatherer, recounting cases in which she used endurance running in hunting.  He sees this as showing: "Hunting is generally a male activity in recent hunter-gatherer societies, but older children and women (the latter unaccompanied by6 children or infants) who were good at endurance running would also have been effective persistence hunters with little risk" (Lieberman et al. 2009: 84, 86).  Lieberman has also written an article arguing that the wider pelvis of women does not impede their locomotion, and that "women and men are equally efficient at both walking and running" (Warrener et al. 2015).  Ocobock and Lacy actually cite this article, but without acknowledging that this denies their claim that Lieberman ignores women's capacity for endurance running and persistent hunting.

This all reinforces my general point that even if men in foraging societies have been predominantly the hunters, some women have often been hunters, even persistent hunters.


Bramble, Dennis M., and Daniel E. Lieberman. 2004. "Endurance Running and the Evolution of Homo." Nature 432: 345-52.

Carrier, David R. 1984.  "The Energetic Paradox of Human Running and Hominid Evolution." Current Anthropology 25: 483-95.

Liebenberg, Louis. 2006. "Persistence Hunting by Modern Hunter-Gatherers." Current Anthropology 47: 1017-25.

Liebenberg, Louis. 2008. "The Relevance of Persistence Hunting to Human Evolution." Journal of Human Evolution 55: 1156-59.

Lieberman, Daniel E. 2021. Exercised: Why Something We Never Evolved to Do Is Healthy and 
. New York: Vintage.

Lieberman, Daniel E., and Dennis M. Bramble. 2007.  "The Evolution of Marathon Running." Sports Medicine 37: 288-90.

Lieberman, Daniel E., et al.  2007.  "The Evolution of Endurance Running and the Tyranny of Ethnography:  A Reply to Pickering and Bunn."  Journal of Human Evolution 53: 439-42.

Lieberman, Daniel E., et al. 2009.  "Brains, Brawn, and the Evolution of Human Endurance Running Capabilities." In Frederick Grine, John G. Fleagle, and Richard E. Leakey, eds., The First Humans--Origin and Early Evolution of the Genus Homo, 77-92.  New York: Springer.

Lieberman, Daniel E., et al. 2020. "Running in Tarahumara (Raramuri) Culture: Persistence Hunting, Footracing, Dancing, Work, and the Fallacy of the Athletic Savage." Current Anthropology 61: 356-79.

Ocobock, Cara, and Sarah Lacy. 2023a. "Woman the Hunter." Scientific American 329 (November): 22-29.

Ocobock, Cara, and Sarah Lacy. 2023b. "Woman the Hunter: The Physiological Evidence." American Anthropologist, 1-12.

Pickering, Travis Rayne, and Henry T. Bunn. 2007. "The Endurance Running Hypothesis and Hunting and Scavenging in Savanna-Woodlands." Journal of Human Evolution 53: 434-38.

Warrener, Anna G., Kristi L. Lewton, Herman Pontzer, and Daniel E. Lieberman. 2015. PLoS ONE 10 (3): e0118903.


Larry Arnhart said...

When I sent a link to this post to Sarah Lacy and Cara Ocobock, I received this message from Lacy:

Both Cara and I were trained in Herman Pontzer's lab, a student of Dan Lieberman, and we both know Dan. We are intimately aware of his arguments and methodology. We've received unrelenting hate mail of various flavors of sexism, including threats of violence and Ted Kaczynski-looking physical mail over the last month. So though your critique is allegedly purely academic, it is hard to receive it as such from someone who is not a human biologist nor anthropologist.
Publish away, but please do not send it to us.

Les Brunswick said...

I think that many people find it hard to be objective on this issue because of of what they believe are its implications for relations between the sexes. On the one hand, male chauvinists use the only-men-hunt claim to justify oppressing women. On the other side, many feminists mistakenly assume that equality between the sexes requires that the two sexes hunted equally.