Future Evolution

Can we say anything about human beings to come? In a word, yes.

Recently after lecturing about human evolution, I had a student come up to me and ask—she apologized first, as some do, despite my mantra that there are no bad questions—if I had any thoughts about future evolution. I did, although I hesitated to offer them; the political correctness monitors are everywhere in universities today. But, casting caution to the winds,

I said what I actually think.

“In the future the species will be more brown and more religious.” She and another young woman with her—both were brownish, smart and pretty—looked bemused, as they were supposed to, and after a pause for drama I explained.

More brown is a no-brainer, for two reasons. First, the species (very fortunately I think) has an unprecedented and rising rate of interracial mating, whether through marriage or other unions. In the U.S., for example, it’s the one measure of improving race relations that has undeniably and steadily risen since the ‘sixties.

Unless that trend reverses, then over the millennia to come global travel and communications can only further reduce the race and ethnic differences that have so long kept gene flow relatively low. No doubt there will always be some people we would still call black, white, red, or yellow, but there will almost certainly be ever-more of us in between.

Second, white people, or Europeans and their descendants, are no longer replacing themselves, and Asians are headed the same way. China may have imposed the one-child family, but Thailand and Italy chose it, and such societies as Japan, Germany and France must import people or fade away. So natural selection will add to healthy mingling in making the species deliciously caramel.

But more religious? Surely this is a cultural feature that could be unpredictably and quickly swept away by a surge of faithlessness or reason?

I don’t think so. First of all, it’s been an inherent part of our species—every culture has had it—since the beginning. True, since then too there have always been unbelievers, but they have been in the minority; not as small a minority as those who came out and said it, but a minority.

So faith is durable. In the early twentieth century it seemed as if Marxist, Freudian, and analytic philosophies were all creating post-religious cultures. None lasted, although in some countries the minorities certainly grew. Today, Western Europeans are about one-third non-believers, one-third traditional, and one-third people of informal or unconventional faith.

But Western Europe is (see above) not replacing itself, and in every major religion the more religious people—especially the fundamentalists—have lots of children. Still, this is cultural, is it not? Education and media can easily bring the European pattern to the world, and eventually reduce religiosity even further. Or can they?

The famous Minnesota Twin Study found that the contribution of genes to the variation in religiosity is about 50%. If this is right, then the opportunity for natural selection is great. Over thousands of generations, even much lower levels of heritability can form a good substrate for evolution.

Levels of heritability for religiosity have varied a lot in different studies, but they may vary according to a pattern. One recent study estimated that the heritability for this measure was 12% in adolescents but 44% in adults, with most of the difference due to shared family environment. How do we interpret this?

It seems reasonable that family environment would cause twins and other siblings to behave and even think in similar ways when they are still responding to parental demands and frameworks. But in adulthood, when they are free to make their own choices, family influence may wane as they tend toward their individual choices.

Under this assumption, we would expect non-identical twins to diverge more as this happens, resulting in a marked increase in estimated heritability to a level that could lead to evolutionary change.

Of course, cultural evolution can be much more rapid than genetic evolution. But I see little evidence that cultural evolution is producing a decrease in religiosity on a global scale; quite the contrary. True, if the world sees a substantial rise in creature comforts for the whole species over the next few millennia, then we could see across-the-board declines in religiosity as well as in population—both in my view positive things.

But more likely in that time frame will be a process of gene-culture coevolution in which much larger family sizes will expand the population base of those genetically inclined to be religious, and at the same time cultural factors will fail to persuade them against that tendency and may even reinforce it.

Of course, stuff can happen—an asteroid impact, worldwide wars over fresh water, or catastrophic human-induced global warming—to change things so much that all bets are off. But in the absence of such drama, it’s likely that several thousand years from now the species will be more religious than it is today, and in general a very pleasant range of shades of brown.


  1. Simon Peron says:

    I have to disagree with this Dr. Konner (obviously not the brown part!) — I think there are several reasons to believe religiosity will decline.

    For one, if we look at development and religiosity, it is a consistent finding that the most developed societies exhibit the lowest level of religiosity and, further, that within societies people who receive the most education and have the highest standards of living also are less religious, on average. And I think what that means is that cultural mega-breeders — i.e., people who are most effective at transmitting their memes — will, on average, be less religious from generation to generation.

    On the other hand, if we do not see an increase in standard of living, etc., then I think it is safe to say we will have some very serious problems on our hand. Weapons technology is becoming ever more accessible and if inequity continues to persist in a world with growing number of fundamentalists then our species is done for anyways.

    As to the argument regarding larger family size among the religious, I would say that first, if they do indeed breed more numerously we will either hit carrying capacity or, due to increased general fundamentalism, succumb to the argument in the previous paragraph. But I just don’t buy into this argument; it is true that there are copiously breeding sects around the world, but I think empirical evidence disproves the notion that they eventually take over. Europe’s Catholics, though they almost certainly have more children than atheists/agnostics, have essentially lost the battle for that continent (to which one could reasonably counter that now Europe is seeing a growing Muslim population, but I still think the general trend will hold, it just may take much longer due to the far higher baseline religiosity of most of Islamic societies). And while one could say that, e.g., mormons in the US have higher fertility rates (this is all anectodal; I have not seen the studies), I still suspect, based on the example of other Western nations, that the improvement in living standard simply outpaces the spread of religion and, in the end, wins out.

    I am curious why you say that evidence suggests worldwide religiosity is rising — is it not perhaps that fundamentalism is increasing, but average religiosity is declining? (i.e., the mean of the distribution of religiosity is moving to 0, but the amplitude of the tail is growing) Because sure, there is a perception, especially with the recent rise of militant Islam, that religion is experiencing growth. But this maybe simply because the extremists are manifesting themselves so vocally that it skews our reading of the underlying data…

    And one final point, perhaps a bit tongue in cheek, but relevant nonetheless. The majority of religions tend to be anti science, especially with regards to manipulating our genetic makeup, etc. I strongly suspect that within the next several centuries, it will be possible through some method to extend human life to a far longer timeframe than is currently possible. Once this happens, two consequences emerge. First, it will force a complete re-evaluation of reproductive rights because it will make the pressure of population unbearable; if you can live in a 25 year old body indefinitely and have children at your whim, children who also can live forever, the scenario becomes ugly fast. Second, I think people who are nonreligious will be more likely to adopt these methods, especially if they tend to be dubbed as unethical by the religious leadership, as many such technologies probably will be. This means that during the transitional period, nonreligious people will live longer, on average, and thereby 1) extend their memetic impact due to longer lifespan and 2) extend their genetic impact.

    But of course by the time this all happens we will all be dead …

    PS — I have been reading this blog since you came to our wedding, and it has been a quite enjoyable experience. Keep it up!

    Warm regards,


  2. Dear Simon,

    Thanks so much for writing, and for reading my blog. I hope you and Mili are as happy and successful as you seemed at your beautiful wedding.

    Some of your arguments are surely cogent, but none is really convincing to me. It’s a matter of arithmetic. If religiosity is substantially heritable, as it seems to be, and the least religious are relentlessly removing themselves from the gene pool, then it doesn’t matter how smart, high in living standard, or advanced in science they are, especially if, as I believe, the correlations between each of those and religion are weak although negative. Genes for lower religiosity will be continually removed from the gene pool. Memes travel faster than genes, of course, but this is a problem in gene-culture coevolution. Perhaps we could try to model it and see what happens under different assumptions? If present trends continue.

    As for your point about longevity, that’s one of those all-bets-are-off game changers, and so not very interesting, but nonetheless, I must admit, possible. The only thing I’d be inclined to predict in that case is a Hobbesian war of all against all. Glad I’m not living to see it!

    Thanks again and warm regards to Mili, one of the few people I know who’s as brilliant as you are.


    PS: After talking with you and Chris at your wedding, I decided to teach that freshman seminar on human nature again for the first time in years. Let’s hope I get lucky again with the quality of the students!

  3. Simon Peron says:

    Dear Dr. Konner —

    Excellent to hear that you are teaching the seminar again — that was hands down the most important college course I ever took, and I am sure that is true for many who took it.

    As to the argument on religiosity, I guess the most cogent argument I can make is belief dilution. Namely, if you assume belief can have a value from 1 to 0, with 1 being fundamentalist and 0 being “soft atheist” (i.e., concluding that there is simply no evidence either way and, therefore, applying Occam to say no god; militant atheists would, if militant enough, also get a 1 since their beliefs are also non-empirical and therefore must be transmitted culturally vs. learned), I would postulate that, on average, transmission of religion in the modern world results in a decline of belief.

    That is, if your grandparents were devout temple goers, your parents may be go regularly but not nearly as much, and you only go on occasion. In the context of a survey of religiosity, I suspect everyone above (arbitrary!) 0.25, say, would claim to be religious. Nevertheless, there is a subtle but very important change that such surveys simply cannot pick up.

    And I think the empirical data backs this up — only a few days ago, they re-surveyed Americans to confirm what’s been happening – a growth in atheists (belief = 0), agnostics (belief = 0.2), and a decline in the religious (belief > 0.25). Moreover, if you look at surveys of religious service attendance, you find that, at least in Europe, the decline has been precipitous (I guess that is a pretty good way to measure belief intensity shifts among the religious).

    I think this all has to do with the underlying causes of religion – for instance, I would not be surprised if there is a correlation between economic hardship and attendance increases; when people suffer, they get religious. But since standard of living, on average, continues to rise, I think there is a weak but nevertheless extant negative correlation between that and religiosity.

    In the end, this is I think an empirical question – we can study trends in religiosity, church attendance, etc., and look for correlations with other societal factors. My feeling overall, though, is that as science progresses, the choice between religion and science will become ever-more acute (just wait until neuroscience figures out consciousness, and the implications on free will, morality, etc., become common knowledge). And I think that people will actually accept science more readily as it fills more of the voids that religion/philosophy fills today. I think history favors this interpretation – since Galileo, religion has had to play catch-up, while people accept more and more the ‘scientific’ view. But who knows … By the time this is all settled we will be long gone. And in that context, for once, I hope the religious among us are correct, because otherwise we won’t get to see how it turns out!



  4. But Simon, you still don’t address the basic long-term issue, which is the large positive correlation between religiosity and reproductive success. The precipitous decline in religiosity in Europe has been associated (for whatever reason) with a precipitous decline in family size, so Europe has had to import many millions of religious people from throughout the world, who duly have large families and bring their co-religionists to Europe in burgeoning numbers. Worldwide, Europe’s <0.25-ers (not to mention America’s) are a drop in the population bucket, smaller every day. In a few decades the world will be half Muslim (overwhelmingly >0.25) and there will be far more fundamentalist Christians and Hindus than there are now. (Although they don’t matter demographically, America’s remaining Jews will be mainly Orthodox.) In my youth (not to pull rank on you) we all had the same model you outline here. Far from fading away, religion has had a huge resurgence, even in the former Soviet Union which we all thought had abolished it. Intellectuals of my grandparents’ generation, from Bertrand Russell to the Marxists to the Freudians to the early Zionists, all thought that religion was on the run. Something is making us <0.25-ers wrong over and over again. Of course, you could be right this time, but I’m not holding my breath ; )


  5. Brian says:

    “but Thailand and Italy chose it, and such societies as Japan, Germany and France must import people or fade away. So natural selection will add to healthy mingling in making the species deliciously caramel.”

    Given that by global standards those are relatively advanced and high IQ populations, I’m not sure that their population decline is necessarily a good thing. Most politicians probably assume that groups are simply interchangeable & importing people will work out just fine. Maybe it will, but there’s no reason or precedent to suggest it will. Particularly if they bring in people with low average IQ which is associated with a number of social problems (see the Bell Curve).

  6. Maren Dameron says:

    Religion is here to stay

    I don’t think I am going to hold my breath either; I have to agree with you, Mel, on this one.

    Consider this: It’s no secret that humans want to feel good. Just look at our attitudes and behaviors concerning sex, drugs, alcohol, “falling in love”, sports events, rock concerts, TV shows, pop songs and movies. Humans “use” all of these means to help them feel good. And when they don’t feel good, humans use these as outlets to express sadness or anger about why they don’t feel good. For some reason (or more accurately, according to some psychologists, for MANY reasons) religion generally makes humans feel good, or at least feel better than those who don’t have religion. Scientists are still trying to figure out why religion seems to “work”.

    Now someone might respond by talking about all the terrible things religion has done on the planet and to its inhabitants, how it’s just a truckload of superstition and fairy tales. If cultures on the planet continue to become more enlightened, scientific and rational, then religion will go away because rational people should know better. And I could counter with all the horrible things atheists have done, or how the results of science and technology have slaughtered more people and decimated more of the environment than any religious peoples have.

    However, I have to echo Mel’s point about the seemingly global resurgence of religiosity even in technologically advanced societies and ask “why?” I go back to my original point: it makes people feel good.

    Sure, like most religions, there are non-religious entities that can help people feel good:
    Social networks for social animals? Check
    Concrete rules in uncertain times? Check
    A resource for finding food and/or shelter for the destitute? Check
    Systems for educating the young? Check

    But, religious institutions offer all of this and more:
    Explanations for injustices? Check
    Paths for finding meaning in suffering? Check
    Methods for allaying fears in dangerous environments? Check
    Non-random causes in a world filled with seemingly random events? Check

    Religions evolve too. Religions that don’t deal with injustice, suffering, danger and randomness effectively do seem to fade away. I think that one reason fundamentalist Christianity is burgeoning in the U.S. is because many of its churches have found new ways to address injustice, suffering, danger and randomness. They are trying to make the delivery of their messages more fun. It is difficult to tell the difference between some mega-church services and a rock concert. “Come to church… rock out… don’t worry… here’s the rules… here’s why things are the way they are… when you’ve tried everything else and still don’t feel good, come on in… have some fun.”

    Injustice, suffering, danger, randomness… Perhaps science or rational thought will find ways to alleviate the bad feelings associated with these issues. So far, it seems that religion wins out, and because of that, I don’t think it will go away.

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