But is that really the right explanation? The rich pulling away from the middle class is also exactly what we would see if test-taking ability has a substantial inherited component, and the American economy is increasingly selecting for people who are very, very good at taking tests. The latter is undoubtedly true, and there's some fairly strong evidence for the former, in the form of studies of adopted kids. Such studies tend to show that adopted kids bear a much stronger resemblance to their biological parents in terms of lots of things, from weight to income to test scores, than they do to their adoptive parents. Once you've hit a fairly basic parenting threshhold--food, health care, touching and talking to your kid, and not physically or sexually abusing them--the incremental benefits of more intensive parenting seem at best small, at worst unclear.McArdle appears to be confused on a number of fronts. First, the manner in which people in our society meet, form family units and reproduce is not scientific. If this were scientific, not only would we be looking at and testing for specific criteria before approving reproduction, we would see weaker stock that we would need to exclude from contributing its genes to the next generation. We would see a marked difference between the children of the power couple, where both parents had high education and high income, versus couples where only one partner had the "power job", versus couples where one partner stayed at home, versus couples who were wealthy simply by virtue of inheritance.
McArdle presents the example of the marriage of Laura Ingalls Wilder (Little House on the Prairie), who she sees as intelligent and bookish, and Almanzo Wilder, who sees as being significantly less intelligent - intelligence apparently defined by academic interest and achievement. McArdle suggests that in the modern era, the couple would have had nothing in common and thus would likely not have met and married.
Laura Ingalls would quite likely have gone to an elite school, and probably graduate school, then moved to a coastal city, and eventually married another bookworm. Almanzo Wilder would be married to someone like him, a hard worker who nonetheless found school tedious and left as quickly as possible. And when their two sets of children showed up at school, their test scores would be very different.It apparently did not occur to McArdle that the outcome is not binary - that genetics are far more complex than the "Brown Eyes vs. Blue Eyes" diagrams she made in fifth grade. She could as easily argue that her example proves that bookishness is a dominant trait, and that if we pair off intelligent, bookish people with those who are not "nearly as smart as" as them, we'll have a nation full of smart people within a generation.
Instead they had one child, Rose Wilder Lane, who became a very talented short-story writer (her collection, Old Home Town, is a very fine and somewhat brutal study of the Missouri town where she grew up.) They could just as easily have had a child like Almanzo, whose talents lay in other directions.
Second, you cannot effect significant genetic change across a culture over the course of two or three generations. If the argument is that tests became important in the mid-20th century, and that good test-takers have subsequently congregated, married, and as a result have produced a population of exceptionally good test-takers, it's fair to ask, what are the genetic components behind test-taking, and how do we measure them? When an individual takes a test prep course and sees a 10% increase in his score, is that because his genes have changed? Also, if test-taking prowess is hereditable and leads to wealth, why does the U.S. have a long history of economically outperforming nations that consistently outperform the U.S. on tests such as PISA?
Third, the fact that some aspects of personality are hereditable does not render environment irrelevant. As a group, children raised in an unsafe, tumultuous home predictably suffer long-term effects from their childhood experiences that are less prevalent in children raised in safe, stable households. When you see significant changes in a population across a generation (e.g., the rise in IQ in Irish children since 1970, or disparity in IQ between children of East and West Germany with the differences dissipating after reunification, it's not only inadequate to say, "What can we do - it's genes" - its obviously wrong and it's a cop-out. People tend to marry within their social class, and they tend to follow a career path modeled for them within their social class and family, with a potentially profound impact on their future earnings.
Fourth, the wealthy remain at an advantage even when you control for personality and intellect. When the economic outcomes for the lowest-performing children of the wealthy meet or exceed the economic outcomes for the highest-performing children of the poor, you can't deny the role of wealth. Winning the lottery doesn't change your genome, but it sure can open up opportunities that were not previously available.
I don't disagree so much with McArdle's conclusion as I do with how she reaches it,
Maybe the answer is not a quixotic attempt to somehow replicate the experience of being raised by two professionals with advanced degrees. Maybe it's to question the great educational sorting, and the barriers it has erected. Of course, I am not suggesting that we should give up on educating our kids, or that education is irrelevant to preparing people for the workforce. But we should ask whether incremental requirements are actually adding value. Because every additional year of schooling we require makes it harder and harder for those who don't enjoy school to compete in the wider world.McArdle's argument does not support either the notion that the wealthy perform better academically because the typical wealthy child enjoys "the experience of being raised by two professionals with advanced degrees", as there are plenty of wealthy people where one or both partners lack advanced degrees, and plenty of middle class families where both parents have advanced degrees. Few impoverished families with two advanced-degree holding parents, and fewer still when you recognize that their transitory period in student family housing or at the very start of their careers isn't representative? Certainly. But none of that directly supports the genetic argument.
It would be helpful, I think, if McArdle explained what she means by "incremental articles". If I interpret that as, "Adding another round of standardized testing," or "Trying to concoct some sort of formula for rating teachers and trying to purge the lowest-performing teachers", then she's right. That sort of reform can make it "look like we're doing something", and may also be very expensive, but is not likely to materially affect outcomes - and we should examine the data, costs and benefits before expending hundreds of millions or billions on experimentation. Similarly she's correct that insisting that people get additional years of education, without any associated effort to ensure that they're getting something of value in exchange for their additional investment of time and money, is not likely to produce meaningful results. But if you look at the German or Irish experiences (or Polish, or certain American immigrant communities, etc.), you can see why its inappropriate to point to an impoverished community and say, "It's their genes" - and can find many examples of that argument being used to deny equal treatment to a population on grounds that, in retrospect, seem absurd.