Nature vs Nurture

My wife chooses sides in the nature-versus-nurture war expeditiously. When our children are polite, she credits her nurture. When they’re rowdy, she blames my genes. But the nature-nurture war won’t be resolved anytime soon.

The gene played a significant role in the great Indian epic, the Mahabharata. Karna, abandoned by his mother, Kunti, and raised by a charioteer, was taught warfare by Parashurama, a gifted teacher with a fiery temperament, who despised warriors and only taught Brahmins.

One day, Parashurama was asleep with his head on Karna’s lap. Karna was bitten by a scorpion but did not move, because he did not want to disturb his guru’s nap. Parashurama, who believed that Karna was a Brahmin, seeing Karna’s blood on the ground realized that he had withstood pain which only a warrior could abide. Parashurama cursed Karna that he would forget his knowledge of warfare when he most needed it. Karna later fought for the Kauravas in the Battle of Kurukshetra. Parashurama’s malediction helped Arjuna beat Karna, which sealed the victory for the Pandavas. Neither Karna nor Parashurama knew about the double helix. The gene is an abstraction which has stood the test of time.

The battle between nature and nurture was never resolved in Hindu mythology. Lord Krishna said that it was “karma”, not birth, which made one a warrior. Yet, Hindus believe in destiny. The Hindu caste system is an example of genomic segregation. As a child, I was counselled that it was unlikely, based on my track record and those of others from my caste, that I would excel in sprinting, throwing javelins, or competitive football. In fact, I received granular advice. My caste (allegedly, I’m a Brahmin) was not adept at entrepreneurship, either. We’re supposedly competent at only one activity – sitting examinations. I became a doctor, and I’m still sitting examinations. I’m unsure if my DNA determined my fate, or if nature locked nurture, that is nature became a self-fulfilling prophesy.

Generalizations hold statistical truths, although it is unclear if nature or nurture, or both, explains these truths. Siddhartha Mukherjee, the author of The Gene: An Intimate History, is a Bengali, known for their literary talents. Perhaps there’s something in the air of Calcutta, in its wild, unpredictable traffic, which draws Bengalis to writing. This is hard to countenance because, superficially, Calcutta looks like any Indian city; polluted, anarchic, yet with a certain order.

If so much is determined by the gene, is anything left to chance? Chance, it seems, favors the genomically prepared. What if chance, if the dice we cast, is also predetermined? Is will only as free as deemed by our nucleic acid overlords? The prospect is at once redeeming and condemning. The gene’s paradox, or genius, is that it belongs to no ideology. If the gene condemns man to certain actions, it also exculpates man from those actions. The gene is loyal to neither conservatives nor liberals. If destiny is encoded, if talent is predetermined, if I could never have become a sprinter no matter how hard I tried, the implications are profound. Perhaps society should, like the sorting hat in Hogwarts, sort me away from the talents that I will never realize. The conservative may rejoice that society is indeed hierarchical. The progressive may feel justified that criminal inclination, for instance, is not the fault of the criminal. Even the egalitarian can take solace in the gene, for is not equality before destiny the ultimate equality?

The gene has a sordid past. Crystallizing twentieth century totalitarianisms, Mukherjee talks about two regimes that took genetic determination to a reductio ad absurdum. The Nazis believed genetic determination was everything; the Bolsheviks believed genetic determination was nothing. The Soviets and Nazis fought over genetic destiny in a war, ostensibly about control, but really between two competing ideologies of what made man, man, what made utopia, utopia. Stalingrad hosted the bloodiest war between nature and nurture.

The gene inspired not just tyranny, but social justice in its most perverse sense – the eugenic movement. Eugenicists, such as Francis Galton, Ronald Fisher, H.G. Wells, dreamt of making society more efficient by genetic centrifuging, or selective breeding. It was actually the dismal economist, Thomas Malthus, who sowed the seeds of eugenics, by prophesizing a doomsday when food would be in shortage because the species would multiply logarithmically. Malthus realized that the first casualty of famine would be the destitute. The eugenicists wanted to spare the poor from their destiny, by removing them. In an ironic twist, the gene thwarted Malthus’s prophesy by allowing itself to be modified in crops, leading to abundance of food and saving Malthus’s hungry generations from starvation and civil war.

Racial hygiene was taken to an uncompromising level by the Nazis. Though unable to stem the tide of the Nazi massacres, the gene threw Nazi ambitions to the wind because the characteristics which the Nazis wanted to propagate – intelligence, physical strength and cunning – are polygenic. This means that more than one gene is responsible for any characteristic, and any gene is responsible for more than one characteristic. The gene may be selfish but it is also fickle, frivolous and temperamental. To distil the gene to perfection is to render it ineffective. Nature, it seems, has a bias towards nurture.

In Aldous Huxley’s Brave New World, the Director of Hatcheries, the only person who self-evidently retained insight in the dystopia, boasted about mass production of embryos by the Bokanovsky’s Process, which yielded the right number of alphas, betas and epsilons, to carry out the labour in the country. Even in Huxley’s dystopia the gene, though necessary, was not sufficient. The babies had to be conditioned. Those destined to manual labor were conditioned to loathe reading books. The conditioning was nuanced because the laborers had to love the outdoors but not the countryside. The director achieved this by making them repelled by flowers but attracted to sports.

Huxley was a realistic dystopian. He once said that modern medicine was so advanced that scarcely a healthy person would be left behind. This was before genetic testing became cheaper than health insurance. Mukherjee reframes Huxley’s statement into a primal question: what does health and disease even mean? As the gene continues to spurn information, we will be given our chances of developing certain diseases, such as cancer and Alzheimer’s disease. This will shift disease from a certainty in the present to a possibility in the future. If our genes roll the dice, will disease be a roll of the dice? Will statistics maketh illness?

H.G. Wells was a more visceral dystopian than Huxley. In Time Machine, he imagined a society which bifurcated into Elois and Morlocks. The Elois were effeminate, emotionally restricted, and in permanent ennui. The Morlocks were not particularly endowed, feared light, but ate Elois. Wells extrapolated 19th century class distinctions took the nature-nurture duo to its logical conclusion. The gene alone did not produce the light-phobia in Morlocks, it was the deprivation of light over several generations. Wells might have been alluding to the most interesting and controversial part of Mukherjee’s tome – epigenetics.

Epigenetics is a plot twister in the nature versus nurture war. Researchers found that starvation changed the genome of Dutch survivors in the Second World War. Children of the survivors produced proteins which protected the body from acute starvation. The environment can leave an indelible mark on the gene. Nurture refuses to be forgotten. The gene is here to stay. The greatest challenge is in accepting the benefits of genetic knowledge, such as gene therapy for inheritable diseases like Huntington’s Chorea, while assuaging fears of parents using gene editing to produce “designer babies.” Mukherjee goes to great lengths to show that our fears, though understandable, are exaggerated.

The battle between nature and nurture cannot be won by any side because, as Mukherjee puts it in an elegant equation: Phenotype (what we are) = genotype (gene) + environment + triggers + chance. That chance still has a role means that choice, the harbinger of chance, is not dead.

Charles Murray, in Coming Apart, warns that American society may irreconcilably be transforming from a class to a caste system. Murray notes an emerging phenomenon in American society: educated professionals marry educated professionals. American society is being garrisoned in much the same way as the Indian society once was. Murray’s premise lies in the highly controversial inheritability of intelligence – intelligent couples have intelligent children. Murray fears that if intelligence becomes segregated, so does society. Even if the inheritability of intelligence is exaggerated, nurture can produce the same effects as nature. If the habits of the Boston Brahmins are systematically different from the folks in America’s Rust Belt, so that their children are more likely to become doctors and lawyers, nurture will ossify society as surely as nature can.

I’ve dissuaded my children from throwing javelins and playing American football, and forced them to focus on chess, spelling, mathematics and literature. The apple doesn’t fall far from the tree. I blame their gene. But their gene may be incidental, an innocent scapegoat, in nurture’s perennial conformity with nature.


This piece originally appeared in The Telegraph.

Saurabh Jha is a contributing editor to THCB. He can be reached on Twitter @RogueRad


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4 replies »

  1. Huge schizophrenia genome wide association study in a recent Science or Nature. @30,000 patients and @30,000 normal controls. They found 108 suspect genes. The most common was the C4 allele in the MHC complex of genes. This was found in 27% of 30,000 schizophrenics and was found in 22% of normals….[sic!].

    [other top genes GRM3–neurotransimitter glutamate and DRD2–dopamine receptor]

    Conclusion: Each of the most commonly associated genes has only a minuscule effect on the risk of schizophrenia….AND these genes are often found–abundantly–in normals.


    Meiosis is like messy sweeping thousands of genes on the floor–during recombination–with a broom toward one haplocyte or the other. A disease occurs when barely more of one type of gene or the other arrives in the egg or sperm.

    And then there is epigenetics causing all kinds of brakes or accelerators on gene expression….sometimes a vertically passed effect, as you mentioned.

    And then look at virtually all the cancers with their tremendous copy number variation and mutation rate….dozens and dozens of differences from “normal”. What is causing all these astonishing genetic variations?

    Are we living in a virtual ocean of mutagens? It feels as if our DNA is getting pummeled and beaten to death!

  2. “Thus, a person’s innate homeostasis and temperament include the effects of the surrounding cytoplasm on the trajectory of the initial developmental processes.”

    e.g., a Random Walk 🙂 Gould’s “Drunkard’s Walk.”

  3. Nurture IS our nature. e.g., see Tomasello (e.g., “A Natural History of Human Morality”). Prosocial behaviors (up to and including altruism — Sorry Ayn) are every bit as adaptive as the localized low-entropy state sub-atomic and atomic forces that beget us our molecular biology (See physicist Sean Carroll, “The Big Picture”). Even better, these cultural evolution adaptions (inclusive of the STEM disciplines) are essentially Lamarkist. Exponentiality, baby (e.g., Moore’s Law writ large).

    BTW, another fine book I just finished that implicitly riffs on this theme is “The Knowledge Illusion: why we never think alone.” They never once allude to Randianism, but the smackdown is right there in the nicely proffered “hive mind” argument.

    “Nature may be red in tooth and claw, but it is not merely so.” — Sam Harris

  4. Remember that the initial genetic recombination from the individual male and female 23 chromosomes occurs within the cytoplasm that existed within the female oocyte. Thus, a person’s innate homeostasis and temperament include the effects of the surrounding cytoplasm on the trajectory of the initial developmental processes.
    With this as the starting point, I offer the following, expanded definition for “HEALTH:”
    . a person’s daily expression of survival is
    . * ENDOWED by the person’s individually unique ‘clusters of human capabilities’, sufficient for survival after birth;
    . * NURTURED by the person’s ‘caring relationships’ originating, initially before birth, from among the person’s ‘family’ who share a pervasive commitment to foster the fulfillment of the person’s caring and learning ‘human capabilities’, especially during early childhood;
    . * TRANSFORMED by the evolving resilience of a the person’s innate homeostasis and temperament in response to the ‘disruptive events’ occurring during the person’s lifetime, as modulated by the person’s ‘extended family’; AND
    . * SUSTAINED by the ‘family traditions’ of the person’s ‘extended family’ and by the ‘Common Good’ of the person’s community until the person’s ‘clusters of human capabilities’ are NO longer sufficient for survival.
    The words surrounded by apostrophe marks are further defined with a commentary at
    . http://www.nationalhealthusa.net/summary/appendix-i-definitions/

    The long standing studies at the University of Minnesota with identical twins, reared apart, since @1930 (among others) document the dominance of genetic heritage for each person’s personality and intellect, after age 40 years. Nurture early on is also affected by social influences, as identified in the definition above as “disruptive events”, family traditions and a community’s Common Good (including its associated social capital). The occurrence of various levels of diminished stability as an attribute of a person’s HEALTH then represents the entry into medical TRIAGE and health care.
    Using this conceptual model, I suggest that the complexity driving our nation’s healthcare is driven 1) by its institutional governance problems, 2) by the increasing disintegration of the each community’s COMMON GOOD and the adequacy of it’s social capital asset, and 3) by the inadequacy of each person’s ‘extended family’ to form the ‘family traditions’ required for adapting to the various stages of a lifetime. The implication is that healthcare reform will NOT be totally successful for improved quality and decreased cost without a concomitant process to invigorate the Common Good of each community for its ability to ameliorate the adverse determinants of health and to support the needs of extended families.
    In effect, the fundamental processes for healthcare reform, community by community, will require 1) a local “new strategy” for equitably available, enhanced Primary Healthcare, the local Common Good and a severe disaster planning strategy AND 2) a nationally structured “risk management” strategy to distribute the institutional economics and implementation responsibilities among the federal government, State government, insurance companies, complex healthcare institutions, Primary physicians and citizens. The costs of healthcare need a reduction from 18% to 12%. Our nation is headed to international bankruptcy on the back of our nation’s excessive cost for its healthcare. The portion of our national economy GDP) devoted to healthcare spending from 1960 (6.0%) thru 2016 (18.2%) has steadily increased 1.98% compounded annually FASTER that the growth of our nation’s economy.