Atheism and the Selfish Gene - Evidence

Homo sapiens sapiens. Lots of them. At Santa Monica Pier.

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Onwards to the evidence!

First, let’s talk about survival. Which of these, Atheism or Theism, leads to longer life? Though I admit surviving past reproduction is not strictly necessary, it’s something we, at least as organisms, are very concerned with and I figure I should mention it. Theism tends to produce the behavior of church attendance; those who do not practice this behavior have a 50% higher all-cause mortality (after adjustment for confounders like smoking and demographics). Over a lifetime, this behavior would add 7 years to the average lifespan (see my previous blog on that). But few of us, Atheist or Theist, are dying before reproductive age. Living 85 instead of 78 is just icing on the fitness cake. The babies have already been popped out, and our fitness as organisms is determined at latest by the time the brats leave home.

What we really care about is fertility rates. How many babies does the average woman produce? There was a paper published in 2008 that compared fertility rates between the memes of Theism and Atheism (or more accurately, they compare those who consider religion important in their daily lives to those who don’t). The adjusted odds* of having more than 2 children are 25% higher in the US and 20% higher in Europe for those who are religious compared to those who are not (1)(this study adjusted for education, income, specific religion, age and marital status). Going a few decades back, it seems the same trends were in place. A well-cited US study in Demography estimated the fertility rate in the 1980’s of white women to be 2.06  in women who attended church weekly and 1.18 in those of no religious affiliation (2)(these numbers were based on surveys done in the 1980’s and were unadjusted; I think the first set of numbers are much more reliable, and these are given to show that this is not just a recent phenomenon). Is this surprising? The data just confirm the subjective notions that old-school Catholics and conservative Protestants have a lot of babies and that nonreligious people are generally low-babied.

So what does this mean? If these data are true, it seems we have an answer to our question. The Theists have greater fitness than the Atheists. The meme of Theism seems to be mutualistic; those who hold it have higher fitness. Theism is adaptive. The meme of Atheism seems to be parasitic; those who hold it have lower fitness. Atheism is maladaptive. 

Remember, I am speaking biologically. Theists, don't go up to your Atheist friends and point and laugh and say, "You're maladaptive!" This statement has nothing to do with worth or value unless you find your worth entirely in your ability to reproduce; I know no one of whom this is true. Maladaptivity also says nothing about truth or virtue. Perhaps Atheism is true and produces people of higher moral character than Theism. It is immaterial to this essay.

This also doesn't address the question of social evolution. One might argue that a society that includes Atheists is more fit than one that includes only Theists. Firstly, I object to treating social evolution with the same gravitas as biological evolution. "Change over time" is a great concept, but the common mechanisms are barely even analogous, let alone identical. Was it Natural Selection that caused the Fall of Rome through the reproductive success of the Vandals? Was it random mutation which produced the Declaration of Independence? Did gene shift spark the Industrial Revolution? Did America win it's independence from Britain because of superior fitness? Does a society even reproduce? In social evolution, is it not supposed to be the organism itself? Secondly, even if we grant social fitness as a valid replacement to biological fitness, it does not change the categorization of the meme of Atheism (not that the categorization ultimately matters). Perhaps an argument could be made that Atheism reduces individual fitness, but increases the fitness of the species as a whole. Then let it be made! The comments box is ready! :)

I expect someone to object to these studies I cited because they are insufficient to prove that Atheism causes low fitness (instead of association and some confounder doing the causing). But if we applied medical standards of causality to evolutionary biology, there would remain no evolutionary biology. It is, by its nature, speculative, having to rely on associations, never able to conclusively prove causality. Claws or eyes or feathers can be associated with increased fitness, or speculated to improve fitness in an environment. The Theory of Evolution was built on association and speculation, not on strict medical concepts of causality. We see increased cranial capacities, and a progression. We infer that larger brains caused an increase in fitness. But perhaps there was a confounder. Perhaps it was really hand structure, not cranial capacity, that conferred the advantage. We can’t be sure. But we’ve got a pretty good association with progression of pre-humans and increase in cranial capacity. And that’s good enough for us. I ask for the same allowance in this essay.

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*Note that this is odds, and not probability. The odds of winning a coin toss are 1:1=1; the probability of winning a coin toss is ½ =0.5.

(1)  Frejka T, Westoff CF. “Religion, Religiousness and Fertility in the U.S. and in Europe.” EUROPEAN JOURNAL OF POPULATION-REVUE EUROPEENNE DE DEMOGRAPHIE 24 (1): 5-31 MAR 2008.

(2) Mosher WD, Williams LB, Johnson DP. “Religion and Fertility in the United States: New Patterns.” DEMOGRAPHY 29:2(199-21). MAY 1992.