r/K selection theory does not justify racism

Last night I was entertaining myself by reading a few of the angry rants I’m always being sent, and a couple of them led me to a simultaneously familiar and disconcertingly off bit of territory — it was people proudly using Science as a warrant for bigotry. It was weird because they were using terms I knew and that were legitimately part of a scientific discipline, but they were using them in ways that were crazy inappropriate and that revealed they actually didn’t understand the science. There are a surprising number of people who are babbling about r/K selection theory on the internet.

r/K selection theory gets its name from a simplified equation that tries to quantify how quickly a population’s size can change. It reduces the number of parameters that affect the rate of change in population size, N, to just two: r, the maximum growth rate, and K (for carrying capacity), the maximum number of individuals the environment can sustain. It leads to this appealingly trivial equation:

dN/dt = rN(1-N/K)

That seems to fit, intuitively. When you colonize a new environment and your population size is very far from the carrying capacity, your best bet is to be weedy and breed like rabbits…and if two species are in competition, the one that will fill up the environment first is the one that can pump out babies the fastest. If you’re in a stable environment that’s at capacity, r becomes less important — there’s nothing new to exploit, population size isn’t going to change much anymore, so K becomes the dominant factor in defining your population limits. So if you’re a dandelion or a sea urchin, spew out great clouds of cheap zygotes, 99.99% of which will die, but you’ll be able to grab a foothold in any new patch of sea floor or suburban yard that opens up. If you’re an elephant or a blue whale, there are never going to be very many of you in the world, so it’s better to invest more in infant care, so that, while you don’t have many of them, your babies are more likely to survive.

The nice thing about r/K theory was that it was so danged simple…and that was one of the reasons it has long slipped out of favor. Its predictive power was weak, because it went too far and reduced populations to too few parameters. Biology is complex, and species have many more strategies for optimizing their success than just how fast they can make babies. This is not my field, but I saw r/K theory decline rapidly in popularity: in the 70s and 80s, when I took and first started teaching introductory biology courses, it was all over the textbooks; and then it slowly faded away. It was replaced with more complex and more accurate demographic models, and a broader study of life history evolution (you want more, you can read about it in Ecology (pdf), again, well outside my field). I rarely encounter the term any more.

Except in one place.

Racist tirades on the internet!

Go ahead and look for yourself. Google “r k selection” and see what comes up. Among the Wikipedia references and a scattering of course pages (which do get it right), I see triumphant declarations from right wingers and MRAs that r/K selection theory proves that they are right. r/K Selection Theory Ends All Political Debate, they announce; all you need to know is a little bit of biology and you can destroy all those liberals. Except the ones that are biologically literate, that is. Would you believe that they are seriously claiming that black people are more like echinoderms and white people are more like elephants, and that being K-selected is superior to being r-selected? Of course you would, because you know they’re stupid. They’re even abusing the theory to claim that different political/religious systems are driven by their misinterpretations of a biological theory.

While Christianity is far more ‘K’ selected than say Marxism, it’s still more ‘r’ selected than the pre-Christian European social orders. An exception to this would be the Roman empire which was based on a pagan belief system, but through its expansion and conquest it gradually became increasingly ‘r’ selected from things like the abundance of sex slaves they kept. This eventually turned into all out sexual degeneracy practiced by many Romans, but especially the elites.

You can’t do that, I splutter. Setting aside the bad history there, the r and K parameters are a simplified (too simplified) abstraction for a lot of biological properties that affect population growth. r is the same in all of those groups; human pairs can pop out roughly one baby a year, but most don’t. K is dependent on the environment as well as the biology of the organism. Because there are multiple factors affecting it, you can’t look at just the number of babies produced and announce that a population is r or K selected; the same organisms with the same r values will grow at different rates in different situations, which is what that r/K formula says. If I put a pair of rabbits on an island with a lot of food, they’ll reproduce rapidly; if I put a similar pair on an island with little food, they’ll reproduce more slowly. This does not imply that there are different r values in the two sets of rabbits.

They do a lot of this kind of misinterpretation and failure to grasp the basic concept. It’s driven by the fact that they also have a peculiar set of value judgements. r is bad, so you take every human characteristic you dislike and assign them to the r strategy. K is good, so all virtues get lumped under that category. This is not biology. Those parameters are abstractions, not descriptions of ethical qualities. K is not synonymous with courage, and r is not the same as promiscuity. You can’t just reify these abstractions to declare that “Person X is like a cowardly little rabbit, therefore he is r-selected, which is a sciencey term, therefore Science has just put the stamp of absolute truth on my assessment.” You can’t do that.

You especially can’t do that because r and K are properties of a species and an environment. But they happily apply them to individuals and categories of individuals. For instance, did you know that some women are r-selected, and others are K-selected? It makes no sense, but it’s all over the place.

With an r-strategy, the quality of the mate isn’t very important; you just spread your genes far and wide. With a k-strategy, you select the fittest mate and monopolize their womb/sperm.

These differing strategies result in differing behaviors and attitudes. A heavy r-woman is a mega-slut (having sex in her teens). She’s bitchy and masculine in her behavior. She’s interested in style over substance (think Jersey Shore skanks).

A heavy k-woman has very few sexual partners over her lifetime. She is feminine and agreeable. She is interested in a long-term, stable relationship with a man of substance.

Wait, wait. So masculine behavior is associated with women being r-selected? Not so fast. It turns out that sometimes not being masculine enough is an r value.

The white (k-selected) population built this country, despite any revisionist history to the contrary, and it is systematically being destroyed, not just by minorities, but by women, and pussy ass men inevitably r-selected by their general lack of aggression/decisiveness. Does this not sound like the modus operandi of r-selection?

I get so confused reading this stuff. Here’s an example of failing to understand what r is, inappropriately applying it to individuals, and being self-contradictory.

*** Feminism is r-type

“In r-type populations, females exhibit more male traits, such as increased size, aggression, and competitiveness. In this milieu, this is an effective aspect of an r-strategy, as r-females need to both provide for their offspring, and fend off threats, due to male abandonment.

It is interesting that modern feminism, so often associated with the left, exhibits a denigrating view of the rewards offered by offspring rearing, an embrace of sexual liberation for women (ie promiscuity), a denigrating view of men which would facilitate short-term mating relationships, as well as an increased drive to compete aggressively alongside males, in traditionally male endeavors.”

You can’t do that. You can’t declare that feminists, who are biologically human, are r-selected, while misogynists, who are also biologically of the same species, are K-selected. This is simply rank nonsense.

But further, this same article defines the r strategy as having lots of offspring. But talk to a feminist: they are all about limiting and controlling reproduction, having fewer children or none, and pursuing other roles in society beyond just making babies. By their own deeply flawed definition, feminism is K-type. But apparently the attributes of these parameters vary depending on sex…which makes no fucking sense at all. They argue that r/K selection theory is an incredibly powerful paradigm, capable of flaying a liberal’s mind faster than any other concept on the planet. I think they’ve confused stupefaction at the demonstration of egregious idiocy by the ‘conservative’ with “flaying”.

Oh, we’re not done with the inconsistencies. Did you know that Homosexuality is a dishonorable mating strategy? On some days, homosexuality is biological futility, doomed to die out as they fail to reproduce, and on others, well, we have to fit this into the r/K paradigm somehow, and r is bad remember, so they’re somehow using this to breed rapidly.

This example finally provides an evolutionary justification for homosexuality. Mimicking a female gives the Anticompetitive cuttlefish access to females, which he would otherwise never acquire. Likewise, almost all human fags are bisexual, and many men become gay only after failing with women. Being gay permits the occasional “experimental” bang with a girlfriend. Hence the K male’s aversion to fags and fag hags.

I don’t even…

Here’s another blatant attempt to coopt science to defend their bigotry. Hatred for liberals is genetic, they say.

“…Competitors who evolved to revile those who violated the Competitive strategy. These groups would easily dominate such a group competition. Individuals that were imbued with a fierce contempt for cowardice, a hatred for selfishness, and aversions towards such behaviors as interference in free competitions between men, opportunistic advantage taking, rule breaking, sexual sneaking and disloyalty to the group would form, and function within, successful groups unusually well.”

In other words, homophobia is not latent homosexuality, it is a rational genetic strategy. As is hating hippies.

You know, none of that follows. It doesn’t even make logical sense, even if one accepts the false premises underlying it.

This bogosity is incredibly popular among the ignorant, however. Would you believe liberals and conservatives can be explained by r/K theory?

For humans, it would be advantageous to be able to switch from one mode to the other as the situation demands. A microbiologist over at anonymousconservative.com thinks that humans do just that. There is evidence, he says, for bit of programming in our brains that triggers a transition from “r” to “K” mode, based on environmental cues. In a 30-page scientific manuscript titled “Modern Political Thought in the Context of Evolutionary Psychology” posted at his website, he makes his case that left-wingers (i.e., American-style liberals) are acting in r-selection mode, while right-wingers (i.e., American-style conservatives) are acting in K-selection mode.

Oh, god. Look at the formula at the top of this article. There is already a switch in that oversimplificat that triggers changes in rates of population growth: it’s N. You don’t have to invent brain programming to do it.

I don’t even understand how, when all you’ve got in the formula is a reproduction rate, you can leap to the conclusion that conservatives are K-selected and liberals are r-selected. Again, it is totally inappropriate to mangle the theory this way, but who makes more babies? Rural Mormon conservatives or upwardly mobile urban feminists?

Note also the entanglement of evolutionary psychology here. This is another common theme: our conservative, exploitive, bigoted perspective is supported by evolutionary psychology and ecology, and therefore it is true. Never mind that EP is a collection of ad hoc myths calculated to justify inequities, and that they have to lie about ecology to twist it to fit their preconceptions.

We can’t just blame this behavior on stupid people engaging in circular arguments to excuse their biases, however. These ridiculous appropriations of an old theory in ecology have also been ripped off by racist cranks and published in the academic literature. J. Philippe Rushton, anyone?

This article discusses the r/K theory of Social Biology and how it relates to humans. The symbols r and K originate in the mathematics of population biology and refer to 2 ends of a continuum in which a compensatory exchange occurs between gamete production (the r-strategy) and longevity (the K-strategy). Both across and within species, r and K strategists differ in a suite of correlated characteristics. Humans are the most K of all. K’s supposedly have a longer gestation period, a higher birthweight, a more delayed sexual maturation, a lower sex drive, and a longer life. Studies providing evidence for the expected covariation among K attributes are presented. Additional evidence for r/K theory comes from the comparison of human population known to differ in gamete production. The pattern of racial differences observed to occur in sexual behavior has also been found to exist on numerous other indices of K. For instance, there are racial differences in brain size, intelligence, and maturation rate, among others. The findings suggest that, on the average, Mongoloids are more K than Caucasoids, who in turn, are more K than Negroids. Recently conducted studies have extended the data in favor of r/K theory, and further research is currently underway, including whether r/K attributes underlie individual and social class differences in health and longevity.

Aaargh, the stupid, it burns. Let’s use some archaic racial classifications, try to update it with some hot new sciencey lingo (this paper was published in 1988, when the r/K stuff was on the wane…but it’s not as if a guy who peddles 19th century racial “science” is going to be very current), and then pretend we’re actually doing research to measure population-specific variation in r values. This is typical Rushton, trying to bullshit his audience with false claims of a scientific foundation for his prejudices.

But it’s an amazingly popular strategem. This is lying with science on a par with what creationists do, and it’s everywhere in the most unpleasantly odious communities on the internet: racists, misogynists, and crank conservatives, all the people who have recently won bigly in the political arena. We should be afraid. And we need to fight back more against pseudo-science.


  1. says

    By the way – if anyone thinks they could write up r/K’s use by scientific racists suitably, “r/K selection theory” is on the RationalWiki to do list with 56 upvotes, and someone just asked on Twitter if we had an article yet. PZ’s given a good selection of cribs to start you off with :-)

  2. says

    Yeah, and it really has become universal shorthand among MRAs/conservative idiots. It’s a good thing we don’t bother teaching it in intro biology any more, because students who googled it would get a grossly distorted view.

  3. says

    Good suggestion in comment 1. I agree.

    Yes, we need to fight back more against pseudo-science, and this “r/K selection theory” is particularly pernicious because it takes advantage of a lack of knowledge in readers.

    The actual arguments in “r/K selection theory” all come with a whiff of desperation.

  4. alkisvonidas says

    I’ve always know the “r/K” equation as “the logistic equation”. Its discrete version, the logistic map, can lead to some very interesting chaotic behaviours.

    AND racist drivel, as I’m just finding out.

    (Population biologist Robert May suggested teaching the logistic map at school, so that students could develop an intuition for mathematical chaos arising from simple systems. I guess he underestimated the power of the daft side)

  5. Knabb says

    “The stupid, it burns” is right. I can’t say I’m surprised by this; mangling the extreme basics of a field while totally oblivious to the rest of the fields existence is pretty typical in these circles and while pulling in ecology at all is somewhat unexpected this is basically the exact same thing that gets done to economics and biology.

    On the other hand, there’s something special about the stupidity involved in simultaneously claiming that white people are dying off en mass as demographics change and that white people are disproportionately K selected, and it’s basically the same group of people. That nobody involved seems to realize that this implies that at a world population of 7 billion and change humans would have to be in the r dominated region is just pathetic.

  6. says

    Oh my. That’s a brain load of nonsense to digest with my tea. While it’s obvious to any thinking person this isht is nothing more than pathetic wishful thinking, there are simply too many people out there who are desperate to shore up their bigotry. Even if this is so thoroughly debunked they find it to be of no use, they’ll just glom onto something else.

  7. says

    These differing strategies result in differing behaviors and attitudes. A heavy r-woman is a mega-slut (having sex in her teens). She’s bitchy and masculine in her behavior. She’s interested in style over substance (think Jersey Shore skanks).

    A heavy k-woman has very few sexual partners over her lifetime. She is feminine and agreeable. She is interested in a long-term, stable relationship with a man of substance.

    But but but butbutbutbut!!!! If they’re saying that biology influences behavior, shouldn’t they accept that since a teenager is equipped by nature to have sex, that that’s what they should be doing?

    I think their problem is that they think the teenagers are having sex with the wrong people, most notably not them.

  8. alkisvonidas says

    Oh, have I mentioned that the r/K model obviously doesn’t apply to humans right now, since we have an overpopulation problem and we nonetheless keep increasing exponentially?

    I know… subtle.

    This reminds me more than anything of Islamophobic theories that claim Muslims are taking over Europe because of their increased fertility. I’d say innumeracy is by far the worst plight affecting us right now.

  9. cartomancer says

    That’s a lot of bad history to pack into three sentences.

    One wonders quite how much this bright spark knows about Pre-Christian Europe. Or the Roman Empire for that matter. Or Christian Europe. Or Marxism. Well, obviously one doesn’t wonder all that hard – it’s clearly bugger all.

    He seems to be working from the old-fashioned cartoon model of the decline of the Roman Empire, where everything collapsed into immorality and freaky sex until nobody could be bothered to fix the aqueducts anymore. Someone has to stand for wanton sexual abandon in the erotic imagination after all, and many Romans themselves were obsessed with policing it. The reason the later Principate tends to get cast in this light is the fact that far more people have have heard the lurid gossip and fantasy stories from Suetonius and (especially) the Historia Augusta than have bothered to find out whether they were likely to have been true or not. That people still still pass on this salacious stuff so uncritically is a veritable triumph for Roman polemic writers, aided not inconsiderably by centuries of Christian castigation – it suited the medieval Christian narrative very well to make “pagan” Rome out as monstrous, immoral, and well deserving of replacement.

    But scratch the surface of any Roman history writing and you’ll find this obsessive concern for moral decline and the corrupting influence of wealth and Empire. Sallust focuses on it. Livy opens with it. Tacitus revels in it. Even Ammianus Marcellinus blames it for the success of Christianity (in his eyes an immoral fad) in the later Empire. I very much doubt PZ’s correspondent knows it, but he is recycling the very prejudices and fears of Romans themselves (albeit in the language of outdated 20th century biology).

    Though anyone who has spent time with Roman funerary inscriptions can attest to the warmth, love and attention that so many Roman children clearly got. With typical pre-industrial mortality rates in full effect it is not a surprise that there are so many children’s graves, and almost all of them have some warm sentiment expressed, however brief. I was in the British Museum the other day and came across one such tombstone (from Roman Britain, so at least late 1st century AD, probably later) that recorded the child’s age down to the very hour – not exactly the kind of thing one might expect from a society that promotes rampant breeding and little care for the resultant offspring.

    I might also point out the tombstone of one Alia Potestas – evidence of an unconventional Roman household from the 3rd century AD where two men lived as the partners of one woman in the same house, but separated and went their separate ways after her death. No children resulted from this family, even though the men’s dedication to Alia veers into uncomfortably sexual territory quite often. This is one true face of late Roman sexual mores – rather confounds the strange r/k nonsense above doesn’t it?

    Mind you, I can’t see the phrase “r-rtype” without thinking back to arcade machines I was rubbish at as a child.

  10. Crip Dyke, Right Reverend Feminist FuckToy of Death & Her Handmaiden says

    I’d say innumeracy is by far the worst plight affecting us right now.

    It might be a close second to the overproduction of radishes.

  11. anbheal says

    Buh buh but…wait a sec. If I’m a PUA, don’t I want to spread my r man-goo to thousands of nubile hotties, and become one of those sultans who sire a thousand manly offspring, and re-make the genome in my own image and likeness? And then have the liberal state apparatus support them, while I waltz off to fuck freely, without any financial burden?

    I’m so confused.

  12. Pierce R. Butler says

    I can’t shake the “rabbits/Kangaroos” mnemonic I invented when first reading such formulations.

    PZ Myers @ # 2: … it really has become universal shorthand among MRAs/conservative idiots.

    Ask them to compare the quantity (and quality!) of Clinton offspring and Trump spawn.

  13. Jessie Harban says

    Wait, wait. So masculine behavior is associated with women being r-selected? Not so fast. It turns out that sometimes not being masculine enough is an r value.

    Oh, it’s simple really.

    Obeying traditional gender roles is something I like, so is therefore K selected. Masculine women and feminine men disobey traditional gender roles, which I don’t like, and are therefore r selected.

    Even when they’re wearing science’s ill-fitting castoffs, right wing bullshit takes almost exactly the same forms.

    But I’ve been inspired by this r/K-justifies-racism nonsense. From now on, anything I like is Quantum and anything I don’t like is Entropy. So instead of saying: “I like writing,” I will say: “Writing consists of individual words and is therefore Quantum,” so my opinion becomes Science™ and therefore objectively true for anyone. Or instead of saying: “Personally, I don’t much care for wine,” I will say: “Wine is formed from the chemical breakdown of grapes and is therefore Entropy,” and through the magic of Science™ my personal and entirely subjective opinion becomes a human universal that everyone must share under penalty of incoherent angry rant.

  14. says

    These differing strategies result in differing behaviors and attitudes. A heavy r-woman is a mega-slut (having sex in her teens). She’s bitchy and masculine in her behavior. She’s interested in style over substance (think Jersey Shore skanks).

    But why aren’t they applying biological fact and saying that the girl having sex in her teens has been equipped by nature for it (as most teenagers) and can breed successfully? What’s wrong with that? Unless the primary complaint is that they’re not breeding with the authors and the authors are pissed off about that.

    Wouldn’t breeding more and younger be a typical success strategy, genetically? So the women (it’s always women’s breeding access these guys care about, isn’t it?) who are more monogamous and chaste are probably making their genes rarer, therefore less viable. Or something…

    I think r/K is just like shouting “QUANTUM”; it sounds very sciency and there’s nothing a pseudoscientist likes as much as sounding sciency.

  15. Marissa van Eck says

    All the fancy science talk can’t disguise what this is: an attempt to put a neutral face on the ages old “filthy, stupid, irresponsible minorities who breed like vermin,” with all the dehumanizing shit that mindset implies.

    I believe I once read on this very blog that the “conservative” brain is unduly influenced by its amygdala, which means these are people who let their disgust and fear reactions drive their thinking. They start with an emotion, one of the basest, and use anything and everything they can get their hands around and pervert to “support” their position.

    It really scares me how much this sounds like the 1860s-1920s eugenics movement.

  16. monad says

    I liked the idea of C-S-R strategists, which seems like it captures the useful part of the r/K dichotomy. Can anyone more knowledgeable say if turns out to work any better? (I mean for describing ecology of species, of course, not for splitting humans where anything real will work poorly).

  17. says

    @15, Marissa van Eck

    I believe I once read on this very blog that the “conservative” brain is unduly influenced by its amygdala, which means these are people who let their disgust and fear reactions drive their thinking. They start with an emotion, one of the basest, and use anything and everything they can get their hands around and pervert to “support” their position.

    It really scares me how much this sounds like the 1860s-1920s eugenics movement.

    Indeed you’ll find a lot of eugenics type talk in places dedicated to compiling “cringe” material.

  18. Dark Jaguar says

    Good… gravy… I never even knew about this, and frankly the math is a bit beyond me, but it seems blatantly misapplied.

    What I can say is it seems clear they’re assuming their own premise when they start trying to apply it to “races” as though we’ve all agreed they are in direct competition and there can only be one winner. As though we’ve all agreed that only caring about the success of your own potential descendants is a positive thing, or that they somehow stop being your descendants if they breed with some arbitrarily defined genetic attribute, or that it would be “bad” if “whiteness” got bred out of the species, that “white” would lose in that event.

    Racists are silly old fools.