Monday, February 21, 2011

Atheism and the Selfish Gene - Evidence

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

<---Previous Post "Introduction"

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.

<---Previous Post "Introduction"
----> Next Post "Objection"
*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.


  1. The reproductive rates are also much higher in 3rd world countries as compared to 1st world countries, the poor versus the rich, and the uneducated versus the educated.

  2. Yes indeed! These things are also true. I'll discuss this a bit more in one of the later posts.

  3. Interesting. There was an article in the London Telegraph (or blog post I suppose) that made a similar argument--that atheists were having less babies than theist; and theists may win out in the end. The last two paragraphs of it were very telling. I disagree, though, that the rise in Christianity was *purely* due to a higher birth rate. That doesn't seem mathematically feasible, but I could be wrong:

    "It’s happened before: Kaufmann believes that Christianity’s rise from 40 followers to 6 million within three centuries had less to do with conversions than with higher birth rates, since the Christians rejected such pagan practises as polygamy and infanticide.

    Today we view the ancient world’s attitude to infanticide as barbaric and incomprehensible, but perhaps future generations will look at our attitudes to abortion in the same way – that’s not because pro-lifers would have won the argument, simply that (in addition to the effect of the Pill) abortion is killing the atheists of tomorrow."

  4. Very interesting ideas! I think I'd agree with you that conversion was very important, at least for the first century of Christianity when exposure to lions and gladiators definitely lowered fitness. Acts records at least several thousand coming to faith in the AD50's through conversion. I'd be interested to see the demographics for the first few centuries.

    "(in addition to the effect of the Pill) abortion is killing the atheists of tomorrow."

    Natural selection is indeed mercilessly consistent.

  5. I think you might want to change your wording here:
    parasite (plural parasites)
    (biology) A (generally undesirable) living organism that exists by stealing the resources produced/collected by another living organism.

    Just because atheists have fewer babies (probably by way of increased level of education) than theists, does not mean the atheism is somehow "stealing" the atheist's resources. You are basically showing your deeply felt but (poorly) concealed antagonism toward people who don't share your beliefs. It's insulting.

  6. You are implying that a meme is not a 'living organism'. But can't a meme be a 'living organism'?

    "any complex thing or system having properties and functions determined not only by the properties and relations of its individual parts, but by the character of the whole that they compose and by the relations of the parts to the whole."

    "in actual existence or use; extant: living languages."

    But the substance of the argument is not in word choice, but in idea. The word choice was not an accidental confession of bias, but intentionally selected to provoke discussion. Your comment is evidence that it has succeeded.

    You're right about my feeling antagonism, but it is directed against ideas and not people. Antagonism to false ideas is at the heart of science (and every search for truth). The scientific method is a series of experiments to attack false ideas, null hypotheses, disproof of wrong ideas. Every rational person ought to have antagonism against ideas he or she believes to be false.

    You assert that Atheism isn't stealing the atheist's resources, yet you offer no argument or proof. If you reject my hypothesis, what do you have to replace it? How do you explain the difference in fitness?

  7. For the atheism meme to be stealing the resources of theists, the resources (in this case minds) would have to be the right possession of theism, before being "stolen" by atheism. Otherwise they would be better described as merely competing organisms in an ecology of minds.

    I would say a more apt substrate for the parasite analogy (and here is my bias/antagonism, since you've declared it's okay to express bias/antagonism for the sake of discussion) would be churches, which take resources (alms) from poor people all over the world.

    This is also not stealing, you will say, as the parishioners give of their lots freely. The question of coercive dogma aside (give or you will go to hell), negating that churches are parasites sets a higher bar for parasitism than can be reasonably applied to the competing memes, since the minds of atheists most certainly give themselves to the atheism meme freely (and often despite the outright coercion of their communities).

  8. This is Dan, by the way. Sorry for posting anonymously. Oversight on my part.

  9. I'm not trying to argue that Atheism (the meme) is stealing resources from Theists (the people), but from Atheists (the people). The meme is robbing the people (Atheists) of fertility. In part 4, I argue that Atheism is a dependent meme (but that's separate from my parasite argument).

    Churches may indeed take tithes from poor people, but "Resources" are invisible to Natural Selection. Whatever the churches are doing, it's causing more babies to be popped out of Homo sapiens who go there. And that's all I'm saying in this article. It's a rather trivial argument, I admit.

    And you're right about Atheism being freely accepted. But such is the case with all memes. You cannot force someone to *truly* believe something. That is another interesting feature about memes which should be further explored.

    Feel free to comment anonymously if you prefer. :)