The genetic and social lottery

As opportunity is equalised, more of the variation in outcomes between people will be due to genetic factors. This may have the somewhat ironic result of reducing social mobility.

I generally take the view that assortment by genetic lottery is no more fair than assortment based on social factors such as being born to low socio-economic status parents. An alternative view is given by Garret Hardin in his famous article The Tragedy of the Commons, when he writes of the private property solution to the tragedy:

With real  estate and other material goods, the alternative we have chosen is the institution of private property coupled with legal inheritance. Is this system perfectly just? As a genetically trained biologist I deny that it is. It seems  to me that, if there are  to be differences in individual inheritance, legal possession should be perfectly correlated with biological inheritance-that those who are biologically more fit  to be the custodians of property and power should legally inherit more. But genetic recombination continually makes a mockery of the doctrine of “like father, like son” implicit in our laws of legal inheritance. An idiot can inherit millions, and a trust fund can keep his estate intact. We must admit that our legal system of private property plus inheritance is unjust-but we put up with it because we are not convinced, at the moment, that anyone has invented a better system. The alternative of the commons is  too horrifying to contemplate. Injustice is preferable to total ruin.

Hardin’s observation that genetic recombination can result in an idiot inheriting millions does not bother me, as the luck involved in everyday existence can have the same effect. While the correlation between income and genetic factors is strong, there is plenty of luck involved, particularly at the high-end of the tail.

However, his proposed alternative, inheritance by the biologically fit, is more problematic. How would we determine who is biologically fit? In the future, the ability to assess traits through genetic testing of the foetus may allow inheritance scales to be set. In the meantime, the correlation between parental and child traits are likely to offer a reasonable match, particularly with the degree of assortive mating that occurs. Further, the accumulation of capital itself is a better test than could otherwise be developed. Why test for the ability to be productive in an economy when you can simply observe it, with the result the reward?

More importantly, what of the incentive effects? Do you want the biologically fit to be given their “winnings” as an inheritance, or would you prefer that they have to work hard to receive it – as they would do if they received no inheritance? The value to society of the biologically fit comes from what they do with their endowed traits. Further, does their value come from prudent use of the capital they hold or from the hard work they undertake to amass it? I tend towards the latter.

* As a footnote, Hardin’s use of the term biologically fit is somewhat different to how the term might be used in biology (ability to survive and reproduce) – given Hardin’s views on population control, those who are biologically fit to hold property are probably not biologically fit in the strict sense at all.

10 comments

  1. “While the correlation between income and genetic factors is strong” WHAT? As a scientist in biology, with a special interesta in the misconceptions of the extreme right in the subject, I am very curious of your reference here! I have been looking and looking for any correlation between alleles and socioeconomic status. Very much looking forward to be informed about in ehat this correlation consistes (presuming we are talking about a correlation under the initial assumption “As opportunity is equalised”). One single exemple even, would be fantastic.

    1. Try the following. Or this, in which monozygotic twins were found to have a correlation of income of 0.56 compared to 0.36 for fraternal twins – implying a heritability of income of 0.4. They are not unique results. The only open question is the magnitude.

  2. That cognitive ability is a biological trait, that our brains are largely the result of our genes, that is quite obvious, but that it is as simple as that intelligent parents pass on their intelligence via “genetic elements”, that is questionable. This might sound like a paradox, but it is actually quite simple.
    Intelligence has been shown to depend on very many genes spread out over the whole genome. Much research has been focused on the genetic basis for intelligence so far no alleles have consistently been associated with cognitive ability. It is rather thought that cognitive abilities depend on the complex interaction between different alleles. Identical twins have near identical genetic and epigenetic makeup and their cognitive abilities are very similar. But between siblings there is very little similarity in cognitive ability, corresponding to not much more correlation then the influence of a common environment (about 0.3)
    Cognitive ability does correlate to mothers cognitive ability, but not to the fathers. So, whether men have intelligent offspring does not depend on their own intelligence but on the women they chose.
    The rearrangement of genes that occur during meiosis disrupts the specific patterns that created the parental cognitive makeup. And although intelligence is highly genetic, the specific combination of different alleles that constituted the genetic base for intelligence in the parent is not replicated in the child. The deck of cards is rechuffled and the outcome depends on the specific combination of cards received from the parents, rather than on the cards themselves.
    So, yes, intelligence is genetic, and intelligence is transferred between mother and child, but that transmission is to a very small extent due to “genetic elements”.

    It is very comic that economists build ideologies on a misconception of heredity.

  3. Come on, that reference doesn’t show how much of familiar inheritance of intelligence that is due to “genetic factors”; co-variance can largely be explained by assortative mating and Maternal effects http://www.nature.com/nature/journal/v388/n6641/full/388468a0.html
    I don’t mind old literature, but if one wants to cite that, one should be very much aware of the criticism and the later corrections to it.

    A child’s intelligence correlates with the mothers education and the fathers social status (about 0.35). The only way to investigate how purely “genetic factors” contribute to the heritability of intelligence is to study children of fathers that have not grown up with the father. This does still not exclude the factor that intelligent fathers chose intelligent mothers, who gives children a better start. The ultimate experiment is then correlating spermdonors intelligence with that of their offspring. That is not done as far as I know. Even that experiment has its flaws (epigenetic modification of sperm DNA due to factors associated with SES for example, or donors age), but it could atleast give an estimate of how transmissible the genetic trait is from parent to child.
    Come back with your “genetic elements” when you have that data. Until then, parental genetic transfer of cognitive ability to their children is just guesswork, or as you put or, sausage.
    I think parental genetic influence of the parent would land on about 0.1 to at the most 0.2. The combination of variants of interacting genes, where different variants affect each other differently, is impossible to predict.

    1. You claim heritability of 0.1 to 0.2 when the paper you referenced estimates 48% heritability in a broad sense, 34% in a narrow sense. Given that papers studying twins raised apart, adopted twins etc – pretty much every available combination – all support a significant heritability, and given that the paper you referenced also supports my contention, my challenge to you is to present one empirical paper which supports your claim that someone’s cognitive ability does not correlate to the father’s cognitive ability.

  4. “Come on, that reference doesn’t show how much of familiar inheritance of intelligence that is due to “genetic factors”; co-variance can largely be explained by assortative mating and Maternal effects.”

    If you were familiar with the literature, you wouldn’t have cited Devlin et al (1997) and snidely stated, “I don’t mind old literature, but if one wants to cite that, one should be very much aware of the criticism and the later corrections to it.” The “Maternal effects model” proposed by Devlin et al was premised on the view that the heritability of IQ did not increase through adolescence. Go read the paper. And then read: Haworth et al (2009) “The heritability of general cognitive ability increases linearly from childhood to young adulthood” and Bouchard (2009) “Genetic influence on human intelligence (Spearman’s g): How much?”

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