Height doesn’t always matter….
How universal are human mate choices? Size doesn’t matter when Hadza foragers are choosing a mate:
It has been argued that size matters on the human mate market: both stated preferences and mate choices have been found to be non-random with respect to height and weight. But how universal are these patterns? Most of the literature on human mating patterns is based on post-industrial societies. Much less is known about mating behaviour in more traditional societies. Here we investigate mate choice by analysing whether there is any evidence for non-random mating with respect to size and strength in a forager community, the Hadza of Tanzania. We test whether couples assort for height, weight, BMI, percent fat and grip strength. We test whether there is a male-taller norm. Finally, we test for an association between anthropometric variables and number of marriages. Our results show no evidence for assortative mating for height, weight, BMI or percent fat; no evidence for a male-taller norm; and no evidence that number of marriages is associated with our size variables. Hadza couples may assort positively for grip strength, but grip strength does not affect the number of marriages. Overall we conclude that, in contrast to post-industrial societies, mating appears to be random with respect to size in the Hadza.
Here’s some stuff from the discussion:
Overall, however, our analysis suggests size and strength are not greatly important when Hadza are choosing a mate. This lack of size-related mating patterns might appear surprising, since size is usually assumed to be an indicator of health, productivity and overall quality. But health and productivity may be signalled in alternative ways in the Hadza, who are a small, relatively homogeneous population. An individual’s health history may be more important than size, for example, and this may be relatively well known in a small, mobile population. Additionally, there may be some disadvantages to large size in food-limited societies, where the costs of maintaining large size during periods of food shortage may be high. Such disadvantages will not be seen in food abundant societies, so that large size may be a better indicator of quality in postindustrial populations. Finally, research on another African forager population found that height is negatively correlated with hunting returns (Lee 1979), suggesting that tall height may not be an indicator of productivity in such economies.
Here’s a chart which shows the proportion of females-taller-than-male marriages by culture:
In a previous post I suggested that the shift from small-scale societies to agricultural societies witnessed a transition from an emphasis on innate individual level social intelligence toward rules and heuristics (in other words, wisdom embodied in the preferences of society and its institutions). External physical characteristics are correlated with “health,” so they’re useful. And those who are not physically attractive can signal their own status and abilities in other ways, ugly fat men can for example buy material signalers to show that they have something going on. It strikes me that the Wisdom of Seinfeld is most appropriate for large urban areas with some degree of anonymity. Quick & dirty signalers to filter and influence one’s choices are critical in the incredibly large number of human interactions possible in these urban agglomerations. By contrast, if George Costanza lived in a village one would know enough about his persona to dismiss a random “pairing” with an attractive woman as an aberration (or, one would know the back-story to this bizarre pairing).
As our modern post-industrial society shifts toward information transparency perhaps we’ll become less “shallow”? Remember the 1995 film Species, the attractive alien character met a handsome male at a night club. She assessed his fitness through his looks to make the initial choice. But later she killed him when she found that he was a diabetic. If she’d been able to access his health profile on her iPhone perhaps he would have been able to live for another day?
Labels: anthropology, Evolutionary Psychology
I read a book about the Pygmies once in which the largest member of the group was taunted for being big, clumsy, and noisy, making him a poor hunter.
That is completely irrelevant to the thread, but I can’t help saying it: pygmies kill elephants by sneaking up on them and jabbing them in the belly with a sharp stake. Wow.
But do the Hadza have the concept of “man hands”? They do seem to care about grip strength…
That’s fascinating. I would have thought that mating based on size was instinctive. Maybe there is hope for short people after all. We just need to get the culture to change.
remember that if selection is really strong you often don’t see much heritable variation in a trait. as it is, height is very heritable. even in developing countries it’s pretty heritable, and in developed nations it verges to 90% heritable. that’s suggesting that unidirectional selection isn’t wiping away the alleles for shortitude. why? could be there’s balancing effects, or shorties emerge from the background genetic load.
That’s a good point. I guess I don’t think about the heritable variation in this case because my own height is due to certain medical history that makes it phenotypic but not genotypic.
There are also presumably some selection pressures against big kids. The total resources they take to grow is larger and if they start off big then giving birth will be more difficult. There may be some degree of distinction in what males and females want in their offspring. For example, assuming a non-monogamous mating system, a male might have more interest in having larger kids than a female will.
joshua, yeah, this might also explain the mix of the variation in secondary sexual characteristics.
I think in an H-G group like the Hadza, the potential for the envious to act violently on their envy is a powerful check on the genetic returns to all sorts of traits.
If the top hunter got lots of (maybe most of) the matings, a mob of the other guys will gang up on him and threaten or carry out violence to “persuade” him to not act so selfishly. Ditto for the guy who’s the tallest, smartest, or who has the best business sense (he’ll be expropriated by the mob).
Only when a society moves to a “natural state” (in Douglass North’s term) do we see a dramatic drop in violence. We also see a sharp rise in inequality, as those who would be ostracized or downright beaten and perhaps killed in an H-G society, are now free to accumulate an “unfair” share of good stuff — material possessions, matings with the young babes, etc.
That explains why there are much greater gains to these desirable traits in agrarian and industrial societies than in H-G societies.
I think the same explains why there isn’t so much assortative mating among H-G’s. Imagine that you’re a short male and you see the tallest man and tallest woman pair up –
“Well, look at those two, trying to hog all of the tall genes for their own children, rather than spread the genetic wealth around! Let’s have a little talk and persuade them not to be so selfish.”
Same goes for sorting on any desirable trait — Look at those two smarties, savvy businesspeople, athletes, hotties, etc.!
Again, high-scorers can only start sorting once a natural state curbs the power of the envious mob to use violence (or the threat of violence) to redistribute wealth, broadly conceived. That can continue into an industrial order too.
A corollary is that you could find greater sorting among H-G’s as the signal of being a high-scorer becomes more private.
Figuring out someone’s height, weight, % fat, and BMI — their deviation from the average, anyway — is fairly easy. Just look. So, any two who tried to sort on these traits would stand out and be ostracized or attacked.
But where someone ranks on hand grip strength isn’t a no-brainer — it requires making lots of rare observations vs. simply sizing a person up. So super-grippers could sort with lower risk of detection.
…pygmies kill elephants by sneaking up on them and jabbing them in the belly with a sharp stake. Wow.
Judging by this, that’s even braver than it sounds.
In many developed societies, progressive taxation serves much of the same function of forcibly leveling out of wealth inequalities as the mob would in HG societies.
Is there a correlation between height preferences among females in modern industrial societies and effective tax rates on the highest earners or more generally between height preferences and the levels of wealth inequality? This could be measured in the US over the course of the 20th century as top tax rates have declined or by comparing the US today to European countries with much higher rates on top earners. My guess would be that females get higher ROI on “investments” in height in societies where individual wealth is more easily retained than in societies where wealth is more communal.
agnostic: Bryan Caplan had a similar idea.
hdl: Bryan Caplan had a similar idea.