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Posted by on Jan 19, 2013 in Critical Thinking, Featured Inc, philosophy | 17 comments

The other genetic fallacy

Many are familiar with the genetic fallacy, a type of fallacy of irrelevance in which original or past context is presumed to be relevant whether or not it is. This is not what I will speak to here, but if you’re interested read more at the wiki.  Recently this image was posted to the /r/atheism subreddit. It illustrates what I would call a different sort of genetic fallacy.. one that pertains to actual genetics:

The quoted top comment reads It’s a shame that he’s gay… Not at all because being gay is wrong or immoral or any of that garbage. It’s just a shame because while the Duggars are polluting the earth every 9 months, we don’t have James Randi out there impregnating women with sensibility.

This idea is all sorts of wrong, and I will debunk it here. To start with, James Randi really does impregnate women (and men) with sensibility. Ideas have turned out to be more powerful than any particular smattering of genes, even Randi’s (don’t tell the other evolutionary psychologists I said so!).
EDIT: I was joking about the above parethetical. I meant to poke fun at the notion that EP’s are strict genetic determinists. 

Skepticism is hard

I’ve seen forms of this “stupid people are reproducing faster than smart ones!” idea dozens of times over the last two decades. Almost always from rationalists, secular folks. This dismays me, because you don’t need to be a genetics expert to see serious flaws in the reasoning. First, if the so-called less-smart people can outbreed the rest, and smartness is heritable, then “smartness” of the Randian sort (or whatever exemplar you wish to use: Stephen Hawking, Carl Sagan, NDT etc..,) would have been eliminated from the gene pool eons ago. This obviously hasn’t happened. Why not?

Genetics: also hard

For many traits a person has, and all complex ones, many genes are involved. For example, tallness. The height of offspring is only partly heritable, even if we temporarily omit nutrition from consideration. Different sets of genes are involved in regulating the growth of all of the parts that can make a person taller or shorter. This is also evident in the observation of variation in body proportions between individuals. Also other genes that may not regulate growth could impact your ultimate height by affecting the building blocks for bones, or the efficiency of your metabolism which takes in calcium and potassium, for example. Another problem for trying to “breed” for something like height is that some genes are only effective when they are all present. It’s possible three particular genes working in concert could affect your femur length. It could be that you only inherited two of those alleles from your parents, which without the third don’t have the major effect. Genes are not like conductors, but players of individual instruments in a great symphony which can never know in advance precisely what other players are present, or what they are playing.

For these reasons, some traits simply can’t be reliably built from genes. If there were such a thing as a gene (or even a few genes) for “attractiveness”, those would have come to dominate long ago. Much the same is true for what we refer to as “smartness” (though we sometimes actually mean competence or effectiveness). There’s one other big problem, too. These traits are not merely genetic, but evidence of a successful developmental trajectory. We value them precisely because they don’t come free with the chromosomes, because they are proof of a winning constellation of factors in a person over time.

The light is not merely in the stars, but in ourselves

Steven Pinker wrote about the decline of violence in human societies in his wonderful book The Better Angels of Our Nature. As he describes, there are many reasons why rates of violence have plummeted over time, but none of them are genetic. Stated simply, we built better societies. We created social machinery to disrupt and displace what used to be the benefits that the use of violence afforded any given individual- we made peace and communion more profitable to individuals than discord and violence. This all happened so quickly that there is no chance that biology or selective pressures for a more modern mind could possibly have been a significant factor. In the evolutionary blink of an eye, humans went from typically brutal lives in which murder was as likely a terminus for any one person as cancer or senescence, to amazingly (if imperfectly) good lives in which our diet is a more sinister threat than any of our neighbors.

In much the same way, I would argue that human societies have gotten “smarter” at least in the sense of increasing markets for specialized and sophisticated skills and knowledge: professional skeptics, NASA engineers, internet application innovators and so on. Modernity permits the existence of lengthy childhoods, schools and universities, and economies that free people from having to produce their own food and other survival necessities such that they can develop their intellectual and creative potentials. So it is that we have our sophisticated technologies and industries, and all without ever having to have had some strange eugenics programs for smartiness. The truth is that any randomly picked group of humans will have about the same potential as any other- whether you pay attention to who the parents are or not. This is partly true because human genetic diversity is so low. We’re just not all that different from each other, in that way. We should care about something far more powerful in human societies than particular genes and breeding.

Ideas > genes

Everyone knows that Mormons typically have large families. This has been true for at least several generations. If we assume that the children are all new Mormons, then Mormons should have over-run at least the western US by now. In fact, the Mormon church today shows very little growth (many suspect it inflates its numbers, and that the church is actually contracting). The Catholic church, also known for promoting large families is contracting slowly. How can this be true? People defect. The reasons people defect are complicated, but basically they’re persuaded by competitor ideas. Ideas travel and replicate at the speed of light. Genes can only replicate at the rate of reproduction, and even then guarantee little about specific beliefs.

We’re getting the causalities backwards, that breeding lead us to skepticism and atheism instead of good ideas and the social freedom to explore them. So stop worrying. Want to make more skeptics, more atheists? Don’t try to do it by having more kids, which not only doesn’t necessarily work, but pales in effectiveness. Ideas can convert billions, how many kids can you make? Have some faith, humanity is pretty damned good. If we just give the next generation our best ideas and the freedom to explore the world, they’ll be just fine. It makes no difference who their parents were.

  • Peter White

    One other factor people forget is that the tendency is always toward the norm. Smart people tend to have smart children but, on average, they will not be as smart as the parents. In my own family I can see how this works. My parents were both quite short. My three sister’s average height is about the same as my mother but my brothers and I are a few inches taller than my father. Over all my family members are still shorter than average but taller than my parents.

    • misdreavus

      Well, you are right. Regression toward the mean works, but only up to a point. If the selection differential between one generation and the next is high enough, you will see some degree of lasting hereditary change. (That is, assuming that environmental variables remain constant over the time period in question.) You only need a few hundred years to generate six inches of difference in height between population A and population B.

      Just use the breeder’s equation and plug in the narrow-sense heritability of the trait being selected for.

    • misdreavus

      Well, you are right. Regression toward the mean works, but only up to a point. If the selection differential between one generation and the next for a given quantitative trait is high enough, you will see some degree of lasting hereditary change over time. (That is, assuming that environmental variables remain constant over the time period in question.) You only need a few hundred years to generate six inches of difference in height between population A and population B.

      Just use the breeder’s equation and plug in the narrow-sense heritability of the trait being selected for.

  • David Pinsof

    “Ideas have turned out to be more powerful than any particular smattering of genes, even Randi’s (don’t tell the other evolutionary psychologists I said so!).”

    I actually think that most evolutionary psychologists would agree with you on this point. In fact, they wouldn’t be interested in studying human nature if they didn’t think the ideas obtained by doing so were capable of having an impact on society. Obviously, cultural ideas move at a much more rapid and potent pace in our society than any kind of mutation. As an evolutionary psychologist, I mildly resent the idea that our group of scholars would admonish you for making such a statement. Evolutionary psychologists, as I’m sure you well know, are not genetic determinists but interactionists.

    • http://www.www.skepticink.com/incredulous Edward Clint

      I was kidding about the “don’t tell the others..”, David. I apologize if that was unclear, I was actually poking fun at the idea that evolutionary psychologists are genetic determinists. Thank you for reading.

  • mcygnet

    Great article! And not for the usual reason I’d say that, which pretty much amounts to, “you sure told them!” This one challenged my own thinking. To me it has always seemed perfectly logical to assume the future belongs to the fecund, especially in our one-person, one-vote system. But your Mormon/Catholic observations make me realize I should simply have done some math.

  • http://cherryteresa.com/ CherryTeresa

    Well said.

    This reminds me of sperm banks that require their donors have certain college degrees. Even as a kid, I didn’t get that. It wasn’t asking the person’s IQ, it was asking about their degree. What if someone had the potential to graduate from Harvard, but didn’t due to economic, social, prejudicial, etc. reasons? What if the person who did get a degree performed poorly and only got accepted due to family ties? Having a father that is biological only (not involved in the kid’s life) doesn’t mean the child will automatically go onto college.

    The reddit comment also reminds me of responses I get from people when I mention that I don’t want to have children, and that if I change my mind and do want kids, I’ll adopt. The response is often meant as a compliment, but it doesn’t really make much sense.

    I’ll admit that I’m sometimes guilty of this type of thinking. For example, I like John Lennon’s music and also happen to like the music of his sons, Julian and Sean. As a kid, it made me feel good thinking that his children not only have musical talent, but that they share genes with John. In Sean’s case, he also shares genes with Yoko Ono and was raised by the two. But I realize I only apply this when it’s celebrity children I like. I look at certain other celebrities, whom I don’t find particularly talented and are the children of famous parents, as only being famous because of their fortunate circumstances and sometimes as being spoiled and unworthy.

    We don’t have to have children to touch the lives of current and future generations. I salute those who do have children that they raise well, but it’s not always a “shame” when someone doesn’t have kids.

  • http://www.facebook.com/TharosTheDragon Kyle Delaney

    But the comment wasn’t necessarily implying that genes are what matter. Randi would surely raise his kids to be great skeptics while the Duggars raise their kids to be ignorant Christians.

    • http://www.www.skepticink.com/incredulous Edward Clint

      I doubt it, given the very specific word “impregnate”, and the fact that there’s no lamentation for Randi not choosing to adopt children and raising them.

      Still, I was just using a handy recent example. I have had this conversation with dozens of people who clearly *did* mean genes matter. That has convinced me that the idea is widespread enough that it needed to be addressed, regardless of whether or not one specific example perfectly represents it the fallacy.

      • http://www.facebook.com/TharosTheDragon Kyle Delaney

        I received two replies to my comment. The first claims that it doesn’t matter how he raises them because it’s the genes that count. Then yours claims the exact opposite. It’s funny how everyone’s so sure of themselves.

    • misdreavus

      Parenting has absolutely no long-term influence on personality or intelligence. Behavioral geneticists have known this for quite some time now.

      (Parenting does, however, influence the religion that your practice from birth — just not your degree of religious fervor.)

      If Randi’s children had turned out to be much like their father, which is quite probable, the intergenerational resemblance would have had very little to do with how Randi raised them. (That is, unless he deliberately starved them or subjected them to gross physical abuse. But not too many people would betray their biological instincts in such a fashion.)

      Raise an adopted child from birth, and he will turn out to be far more similar to his biological parents than he is to yourself, in spite of all of your best efforts. The apple scarcely falls far from the tree. Whatever environmental factors influence adult personality have little to do with variation in parenting within a culture.

      • http://www.facebook.com/TharosTheDragon Kyle Delaney

        Okay, that’s weird. Isn’t the point of this article that the genes aren’t what’s important?

  • misdreavus

    Considering that the adult heritability of IQ (or any other measure of cognitive ability, really… they’re all positively correlated) in the industrialized West is roughly 0.75, we have *every* reason to believe that the stupid are outbreeding the intelligent. We have statistics available for TFR by educational level, degree of religious fervor, and income. I suggest you google them.

    Then again, heritability estimates are a mere snapshot in time, particular to a range of genes and environments. Maybe some genius in the future will discover an environmental intervention that may compensate for the deterioration of our collective germ plasm (to echo Linus Pauling’s sentiments), but we live in the here and now — not in one of the many alternative realms of possibility.

    • http://www.www.skepticink.com/incredulous Edward Clint

      “…we have *every* reason to believe that the stupid are outbreeding the intelligent. ”

      How would you explain the recent (in evolutionary time) rise of secular & intellectually healthy societies? If your premises are correct, then at every generation the lower IQ genes should have won out. Yet, secular nations with normal/high IQs and scientific/academic prowess emerged anyway: north & west europe, Japan, Australia, Canada, etc.., These changes can’t be explained genetically, but if you think so, then by all means fill me in.

  • misdreavus

    As for sperm banks being stupid for requiring that donors have a college degree, well, all of the longitudinal adoption studies say they’re right on the money. So do all of the robust twin studies. Hell, if being adopted by wealthy parents isn’t enough to raise your adult IQ, what is?

    As it stands, the most reliable way to have smart kids is to have children with a well educated spouse — even if you were left to raise them entirely on your own. Early childhood stimulation won’t do it. Learning a second language won’t do it. Musical programs won’t do it. Expensive private schools won’t do it.

  • http://www.facebook.com/profile.php?id=5310494 Sam Dangremond

    Have you read “Farewell to Alms”?

    It has lots of data supporting the opposite thesis.

    • http://www.www.skepticink.com/incredulous Edward Clint

      No I have not. Thanks for the reference.