Gene Expression

Why human nature matters

People often assume I’m a “genetic determinist” because of my close attention to the interface of our species’ biology and behavior. I’m also focused on evolutionary science, a discipline where noise, error, and diversity generated by a constellation of variables is assumed (and to some extent, essential). From my interest in the latter it can be easily inferred that I don’t think there is anything necessarily deterministic about how mind and society manifest themselves over the course of development. Rather, an understanding of human nature can make us aware of the constraints and biases which might exist in terms of how we behave and why our societies develop as they do (the many channels of canalization). Evolution is in part stochastic, it isn’t necessarily a deterministic process where knowledge of initial values of the parameters can tell us the exact path of development. But, the stochasticity itself can be quantified and accounted for so that we may comprehend the range of possibilities across which the course of development may vary. One person’s noise is another person’s music.

In a classical population genetic model if you have finite population demes which in the initial generation exhibit a balanced polymorphism of two alleles, A & B, and allow random genetic drift to operate as the sole evolutionary force you can expect that half the demes will fix for A and half for B. You can not predict the trajectory of any one deme, but you can make a general characterization of the evolutionary dynamics operant across the cluster of demes. Additionally, if you have two groups of demes where one set tilts toward allele A and the second toward allele B, you can expect that the former will yield more demes fixed for A than B, and the inverse for the latter. I said expect, because as you can expect that a series of coin flips should converge upon a 50/50 ratio of heads & tails, there will also be an expected deviation from this expectation given a particular of number of trials (as the number of trials increases the deviation verges upon zero). Nevertheless, despite the lack of determinism, there is no implication here that the full sample space of possibilities are equally probable.

This is to be expected as biological sampling processes are natural, and nature is characterized by patterns and rules which bias the outcome of phenomena. The range of states often exhibits a distribution of different frequencies of said states. To move the discussion in a more concrete direction, consider for example a landscape characterized by topographic diversity, with mountains, rivers, floodplains and hills. Where should you build a town? Where could you build a town? Obviously the answer to that question depends on your considerations. Do you want a fortified citadel? A hill would make a good choice then. Do you want access by water? If the river is navigable that location is an obvious choice, but if you build upon the floodplain then you also introduce the possibility of flood damage. Perhaps there is a religious reason you would want to build on the side of the mountain. Certainly gravity would pose problems (dependent upon the grade), but, assuming the right engineering and materials investment it is a possibility. These considerations, the weighing of costs and opportunities in the framework of our values and expectations, come to us naturally when talking about geological constraints. But why shouldn’t the same apply to biology? The adaptive landscape is attractive precisely for this reason, it visually represents the nature of the topography across which dynamic processes flow. A bundle of heritable traits, cognitive biases, historical & personal contingent conditions, all these are parameters which are collected within the richly textured multi-dimensional space of possibilities for our species. Any given locus upon the landscape is characterized by various tradeoffs, stabilities and slopes.

In other words, the range and distribution of our social and psychological variation is not arbitrary. There may only be a finite set of stable social and psychological peaks, morphs if you will. These peaks are characterized by different stabilities, and alternative suites of costs and benefits. We are likely to evaluate the alternatives based upon the values we bring to the table a priori. Nature does not dictate the choices we make, but it definitely may have a hand in pairing down our list of options, or at the least forcing upon us various costs for each option. Though cognitive psychologists have adduced that there is within our species a basal and common moral sense, the playing out of that moral sense within our current societal context is modulated by a host of other parameters. Concrete is raw material, what use you make of it is your own business. In the specific case of morality theists often ask me how I can “justify” any set of ethics without God as a common grounding, but they do not comprehend that for me “God” is no answer at all. As an atheist I believe that the resonance of “God” in the mind of my fellow citizens is an emergent property of natural forces. Though it has much more emotional resonance than the mountain up the valley, God has, in my mind, has about as much to do with our morality and ethics. It is fundamentally a dodge, a non-answer which claims to be the answer wrapped within an inscrutable ball of supernatural mystery. In the end we are still faced the questions brought up by our natures and the products produced by ratiocination operating upon the raw material which we are dealt. Similarly, those who wish to engineer societies and play as gods must take into account the validity of the analogy with engineering: engineers operate within the constraints of physics to design their machines. They will take a set of specifications and implement machinery which can fulfill those specifications, but they do not do so by magical wizardry or purely through trial and error. Asserting, demanding and wishing is not enough. To solve a problem one must account for as many parameters as possible, to arrive at the science of the probable.

Comments

  1. #1 coturnix
    June 2, 2007

    There are two hypotheses (not mutually exclusive) for why people think you are a genetic determinist:

    a) you used to be but have learned better over the past few years.

    b) all the deterministic crap getting posted on the Classic Gene Expression blog (and in the comments there) which you, silently, endorse by not deleting it. You ARE identified by what goes on there, even if you personally do not agree with all of it.

  2. #2 Caledonian
    June 2, 2007

    Not removing comments which express sentiments that you don’t agree with in NO WAY constitues an endorsement of those sentiments.

    Are you seriously suggesting that razib should only permit people to express positions and opinions that agree with his own?

  3. #3 coturnix
    June 2, 2007

    Not comments. Posts by co-bloggers on the Classic (not here). Some our outright racist or sexist.

  4. #4 Caledonian
    June 2, 2007

    Originally posted by coturnix:

    all the deterministic crap getting posted on the Classic Gene Expression blog (and in the comments there) which you, silently, endorse by not deleting it

    Are you retracting your statement about the comments? It’s what you said, after all. Perhaps you’ve changed your mind about their inappropriateness, and if so you should make that clear.

    I also request links to several examples of things on the Classic blog you think are racist and sexist.

  5. #5 razib
    June 2, 2007

    speaking of deleting comments, let’s just end this line of conversation here ;-) and focus on the core of the post. yes, i do delete comments which go “over the line.” but a large number which i’m sure bora would consider sexist or racist (including some of my own) i feel are totally fair game, i don’t really care about that. re: genetic determinism i’m talking about people who are just naive about biology who don’t have issues with my “racism” or “sexism.”

    my favorite example was on ikram saed’s old weblog where we were talking about religiosity. i offered that it was 50% heritable as a character. ikram termed me a genetic determinist because of this assertion as a counterpoint to his self-described social determinism where he ascribed 100% of the outcome to socialization. there is of course an immediate problem with the dichotomy, while i attributed half the variation to genes and half to society ikram ascribed it all to society, but both were tarred with the same extreme label. additionally, there is the complication that heritability is about the variation within a population assuming particular environmental controls, not a tight genetic specification like the number of fingers on your hand. i’ve had to repeat the definition for heritability over and over on my blogs because even regular readers get confused about it (e.g., they assume that 50% heritability means that the trait is “half genetic,” which isn’t really what it means).

  6. #6 Agnostic
    June 2, 2007

    If someone really doesn’t get what you’re saying, you can use two easy examples:

    1) What particular language you speak is pretty much up to what environment you grew up in, but the reason that rocks and cats don’t speak human languages despite being located in these same environments is that the former lack genes of any kind, while the latter lack alleles of the human kind, relating to language.

    2) To push the issue away from the touchy territory of homo sapiens, take a classic example of an interesting, complex trait that looks pretty much environmentally determined — the “helmet-headed” morph of Daphnia. Individuals only develop the protective helmet-head when exposed to cues that there are lots of predators in the local waters (and perhaps also when raised in particularly turbulent waters). Still, the reason why rocks and other organisms in the same waters don’t develop helmet-heads is due to genetic differences. More, the helmet-heads develop into a predictable shape, not just any old shape. Again, genes.

    Genetic differences also account for why social humans, but not solitary cats, engage in the bald-faced peer pressure tactics that Coturnix prefers, as well as for why some human individuals are vs. are not susceptible to this type of social shaming. Fortunately for human civilization, great scientists and artists rarely withdraw from exploration just because it will get them invited to fewer dinner parties.

  7. #7 Agnostic
    June 2, 2007

    The last paragraph should read, genetic differences also account in part for…

  8. #8 cuchulkhan
    June 3, 2007

    A shocking lack of discussion of the human beast exists among the chatterati. All political policy discussions should start with the simple question – what, at bottom, is man, this thing we are trying to get to manipulate?

    Coturnix

    This blog doesn’t endlessly qualify every little point about human nature (a waste of time) – it assumes readers are smart enough to realize genes are not destiny, but are very important.

  9. #9 Caledonian
    June 3, 2007

    it assumes readers are smart enough to realize genes are not destiny

    Except, of course, for all the times when genes ARE destiny.

  10. #10 p-ter
    June 3, 2007

    There are two hypotheses (not mutually exclusive) for why people think you are a genetic determinist:

    a) you used to be but have learned better over the past few years.

    b) all the deterministic crap getting posted on the Classic Gene Expression blog (and in the comments there) which you, silently, endorse by not deleting it. You ARE identified by what goes on there, even if you personally do not agree with all of it.

    c) some people don’t actually bother to think about what the words “genetic” and “determinism” mean, especially when placed in such a confusing combination.

  11. #11 cuchulkhan
    June 3, 2007

    “Your spirit is ashamed that it must do the will of your entrails and follows by-ways and lying-ways to avoid its own shame.”

    Nietzsche, Thus Spoke Zarathustra.

  12. #12 cuchulkhan
    June 3, 2007

    It’s been a long time since I read it but I remember Will Durant’s brilliant ‘The Story of Civilization’ had a great introduction. It placed man in his evolutionary context and argued that the best civilizations were those that adapted themselves to man’s unchanging nature. He was strongly influenced by Herbert Spencer, whom he thought unfairly victimized by academia.

    Durant predicted that interest in Spencer would inevitably return. Spencer certainly touches on many of the issues discussed on this blog. Durant’s chapter on him in ‘The Story of Philosophy’ is a must read.

  13. #13 Ikram
    June 4, 2007

    I think the post you’re talking about is here (scroll to February 25, 2004) andyout response was in the (now lost) comment thread. I think you mentioned the heritibility of interest in religion, but I’m not sure you mentioned 50%. (Looking back — is the concept of heritibility relevant in discussing your specific experiences versus Aniraz’?)

    We’re talking here about a 4 post comment thread posted 4 years ago on an obscure, ill-frequented blog. Had I known I was going to be so memorable (even as an exemplar of biological naivite!), I wouldn’t have deleted the archives.

  14. #14 razib
    June 4, 2007

    I think you mentioned the heritibility of interest in religion, but I’m not sure you mentioned 50%. (Looking back — is the concept of heritibility relevant in discussing your specific experiences versus Aniraz’?)

    you were talking about how my experiences (in the comment thread) at a madrassa had a specific impact on my outlook and religious orientation. i just pointed out that religiosity was .5 heritable by citing bouchard’s data. and yeah, it would be heritability.

    Had I known I was going to be so memorable (even as an exemplar of biological naivite!), I wouldn’t have deleted the archives.

    look, i tell all my readers that they should note what they say because i will remember ;-) this is a feature of my “real life” personality which carries over into blog world. it isn’t the prettiest aspect of my personality, depending on how you look at it, but in the context of blog comments i think it is beneficial since it makes people consider what they’re saying. i even have a little dossier of IP addresses to keep a watch on in case people switch their handles.

  15. #15 Ikram
    June 4, 2007

    OK — and this is a naive question — but can heritibility be used when looking at variations between 2 individuals? Isn’t it a population-level concept?

  16. #16 razib
    June 4, 2007

    but can heritibility be used when looking at variations between 2 individuals? Isn’t it a population-level concept?

    on an individual scale it isn’t really coherent or precise, but, the point i was making in response to your tabula rasa assumption regarding religious orientation is that there is evidence for a genetically controlled component. i obviously wasn’t saying that 50% of the character within an individual is “due to genes.” also, you can figure out expectations for individuals selected out of a given population via the breeder’s equation. e.g., assume that height is 50% heritable. if the midparent mean of the parents is 2 standard deviations above the norm, you’d expect the average value of the offspring to regress 1 std back toward the population mean (of course, lots of variance for this because the N is small).

  17. #17 dougjnn
    June 6, 2007

    I think it’s abundantly clear Razib to anyone with any substantial intelligence who doesn’t have some political, religious or other dogmatic axe to grind, that you are not a simple geentic determinist.

    You’re always talking about the interplay of genes and environment / culture.

    Agnostic, I like your human language illustration. It’s short, neat, simple and powerful all at the same time.

The site is undergoing maintenance presently. Commenting has been disabled. Please check back later!