Let’s get a little behavior genetic

By Razib Khan | January 16, 2013 11:41 pm






1) A substantial proportion of the variation in I.Q. and personality is heritable in a genetic sense. Many observations of parent-child similarities presumed that they were due to learning and emulation, but statistical analysis suggests this is not the case. Today, with genomic understanding of sibling relatedness (recall that though siblings should be related 0.50, there is some variation about this value) this seems more true than ever; much of the difference between siblings seems to be due to the variation of their genetic make up.

2) Most of the “environmental” variation is not accounted for. It could be non-shared socialization. Peer groups as Judith Rich Harris of The Nurture Assumption would argue. It could be gene-gene interactions, which for technical reasons are captured as “environmental” variance. Or developmental stochasticity in utero. Sending your children to Waldorf or Montessori is unlikely to do the trick.

This has real life consequences. Melinda Wenner Moyer repeats the often mentioned fact that people from upper middle class backgrounds in the United States tend to use many more words around their children than those from deprived backgrounds. From this we draw the conclusion that this is why the latter group of children are less verbally intelligent later on. I was curious about this literature, and this article seems representative. I find the presupposition that parents are overwhelmingly important in a child’s cognitive development through their model rather unpersuasive. My own most probable case judgement is that this factoid is one of the ways that the American cultural elite is going to try and dismiss unpleasant possibilities. Primarily, that the early and late life variation in linguistic complexity and intelligence is just a reflection of the reality that class is somewhat correlated with heritable human inequalities. On average those on welfare are less intelligent than those in the professional class, and that is in part due to genetic endowments.* I don’t believe that most Americans today find this argument edifying,  so they are open to any alternative explanation to bridge the gap.

The norms and values of upper class or privileged elements have varied over time and place. Similarly, the norms and values of lower class or underprivileged elements have varied over time and place. I would wager (in fact, I would wager real money) that the gap between the higher and lower orders in other cultures and societies in verbal frequency is going to be very different, because the norms in those societies are going to be very different. Early modern Western elites who had their children raised by their household help nonetheless produced offspring who reflected their own values by sending them to boarding schools and other institutions which shape outlook and character. Culture is not just a matter of parents talking to their children between the ages of one and five.

The most high impact choice you make in shaping the character and aptitude of your children is in choosing your mate. This may be the best argument for taking a PLUS Loan and sending your child to an elite private institution if they weren’t able to get into Berkeley. That way they are guaranteed to swim in a mate pool which is enriched with individuals with the qualities that you are interested in for your grandchildren. And indirectly this may actually be an argument for sending your child to an elite preschool: because in the near future that credential may be the key which opens the gates for the schools which are pipelines into the ruling class. First primary, then secondary, and finally tertiary education.

I am not excited about ending on a down note, but the ridiculous “signalling” which parents do by purchasing useless preschool educations for their offspring may actually reflect the fact that the broad upper middle class is winnowing, as a ‘winner-take-all’ dynamic begins to become the norm. If that is the case then even trivial marginal gains may be important in the competitive scramble for finite resources. The pressure-cooker of elite upper middle class American life may simply reflect the reality of a ‘flat’ and ‘globalized’ world where 200 million Chinese college graduates are coming onto the market. In that scenario even if expensive preschools are useless in the short term, they may be essential in getting into ‘the game.’ Whether this forecast is true or not is not about genetic destiny, it’s about the broader social values which we as a society adhere to.

* I’m willing to put down $500 right now that if you measure the I.Q. of siblings in upper middle class homes at the age of 5, that those with lower I.Q. values are much more likely to end up in the lower class. I would also make the inverse bet. Smart siblings in the lower class are much more likely to go up the class ladder than stupid siblings.

CATEGORIZED UNDER: Behavior Genetics
MORE ABOUT: Behavior genetic

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