IQ, The Brain, and Mencius: "Think about barley."

    Richard E. Nisbett has a nice op-ed in today's NYT, "All Brains Are the Same Color," in which he counters those who want to argue that intelligence (however it is defined) is primarily genetically determined:

In fact, the evidence heavily favors the view that race differences in I.Q. are environmental in origin, not genetic.

     He goes on to describe various ways in which research provides support for the importance of environmental factors in shaping intelligence.  It is nice to see this refutation of genetic determinists in such a prominent venue, since it brings to wider public attention some of the points, such as the Flynn effect, that are made in much greater scientific and statistical detail by Cosma Shalizi (notice, too, Shalizi's take down of the inept William Saletan).

     In any event, this line from Nisbett's article jumped out at me:

In any case, the degree of heritability of a characteristic tells us nothing about how much the environment can affect it. Even when a trait is highly heritable (think of the height of corn plants), modifiability can also be great (think of the difference growing conditions can make).

    Made me think of Mencius, who, in a rather similar argument, tells us to "think about barely.":

Mencius said: “In good years, young men are mostly fine. In bad years they’re mostly cruel and violent. It isn’t that Heaven endows them with such different capacities, only that their hearts are mired in such different situations. Think about barley: if you plant the seeds carefully at the same time and in the same place, they’ll sprout and grow ripe by summer solstice. If they don’t grow the same – it’s because of the inequities in richness of soil, amounts of rainfall,or the care given by farmers. And so, all members belonging to a given species of things are the same. Why should humans be the lone exception… (11.7)

      I can imagine that hard-core genetic determinists will argue that people are not plants and that there is a certain genetic variation within the human species.  But, ultimately, all of that matters much less, the science tells us, than environment, "... the inequities in richness of soil, amounts of rainfall,or the care given by farmers."   Mencius, the ancient thinker, is closer to contemporary reality than The Bell Curve people.

     Think about barley.

Comments

[BigDon]

The barley analogy is not applicable. In humans, genes and environment *synergize* - they are not independent variables. Smarter humans have the capability to seek better environments for themselves and their children. Simplest example: having enough sense to come in out of the cold. Barley can't do that...

[Sam]

BigDon,
Good point. You may be right: humans are capable of conscious interactive effects. But...the barley analogy is still useful, I believe, in countering the genetic determinist position. Thanks for commenting.