Several people have now been kind enough to email me a link to a recent article by Chet Richards, discussing this New York Times piece:
Expressing Our Individuality, the Way E. Coli Do – New York Times
We humans differ from one another in too many ways to count. We are shy and bold, freckled and pale, truckers and hairdressers, Buddhists and Presbyterians. We get cancers in the third grade and live for a century. We have fingerprints.
Even among simple forms of life, like the common bacterium E. coli, genetics only partly determines what any one organism is like. E. coli expresses its individuality in many ways. All the bacilli above are genetically identical, but the shades show differences in the production of proteins that digest lactose.
Scientists have only a rough understanding of how this diversity arises. Some of it stems from the different experiences we have, from our time in the womb on through childhood and into our mature years. These molding influences include things like the books we read and the air we breathe. Our diversity also stems from our genes â€” the millions of typographical differences between one genome and another.
We put a far bigger premium on nature than nurture when it comes to our individuality. Thatâ€™s one reason why reproductive cloning inspires so much horror. If genes equal identity, then a person carrying someone elseâ€™s DNA has no distinct self.
I think some of the concern against genetics comes from not knowing or accepting the fundemental dogma of all social science: that all variation in human behavior can be explained in terms of independent variables.
There’s some straight genetic effects, straight environmental effects, straight epigenomic effects (such as the Dutch kids was limited working memory at birth, because their mothers were born during famine years), but a lot of stuff is complicated.
So now it’s labeled as “individual variation,” which just means “error.”
It seems that the psychometricians can explain up to 80%+ of variation in IQ in older adults by known factors now. IQ’s been intensively studied for a century, but as more and more is done by pharmaceutical companies because there’s money in knowing what causes those variations, I wouldn’t be surprised if we get up to that level of precision for other things soon.