James Heckman is a Nobel prize-winning economist who works at the University of Chicago. In this article, Interview with James Heckman by Douglas Clement in the Federal Reserve Bank of Minneapolis publication The Region (don't say I don't cast a broad net to find the facts behind reading), from June 2005.
The interview and topics are broad ranging including discrimination, education, and IQ among many others. What is refreshing is the constant effort to remain grounded in demonstrable facts, the recognition of the limits of data and the capacity to confront all possible interpretations of data. Among some of the observations that dovetail with our research that led to the Growing a Reading Culture report are the following.
Pertinent to the arguments for greater content in children's reading as well as to E.D. Hirsch's arguments regarding the importance of Cultural Literacy:
Region: What have you found in your own research about the effects of schooling on test scores?
Heckman: Very strong effects, much stronger than what Herrnstein and Murray claim in their book [The Bell Curve]. In a paper published last year with Kathleen Mullen and Karsten Hansen in the Journal of Econometrics, we found substantial effects of an extra year's schooling on the Armed Forces Qualifying Test, the same test they used. The point is that the test they used is an achievement test. It embodies knowledge that people acquire through experience.
[snip]
Region: So it's not nature versus nurture, but rather nature with nurture.
Heckman: Exactly. It's an interaction. Epigenetics is the field that studies this. There are a lot of recent books and scholarly articles on this topic. I was just at the National Institutes of Health last weekend, and part of the discussion we had there was about this. It's a fascinating field.
The people who favor genetic explanations of social phenomena need to be careful about two things. The methods they use for determining heritability assume additivity. They don't allow for interaction. Secondly, when one does the standard additive analysis for different socioeconomic groups, one finds that the socioeconomic status critically affects the so-called heritability coefficient.
A paper published in Psychological Science (2003) by Eric Turkheimer [et al.] shows very strong family background effects on a number of heritability coefficients. Richer families are providing ways for children to override some defective genes and enhance those genes that are productive. We are just beginning to understand these mechanisms. They are very important.
[snip]
Heckman: There's a very strong bias among economists against some of the basic findings of the child development literature. Many economists assume that family effects operate primarily through cognitive child ability. A lot of formal economic models view the development process solely in terms of raising IQs. Or else they assume that IQ is purely heritable. Neither view is correct.
Enriched early intervention programs targeted to disadvantaged children have had their biggest effect on noncognitive skills: motivation, self-control and time preference. We know that there's a scientific basis for this finding. The prefrontal cortex, which is a center of these noncognitive skills, matures late. The executive function, the very definition of ourselves as people, the way we motivate ourselves, these things are malleable until quite late stages - into the 20s, according to research by neuroscientists. This means that in principle we can modify these behaviors. Noncognitive skills are powerfully predictive of a number of socioeconomic measures (crime, teenage pregnancy, education and the like) as I show in a recent paper with Jora Stixrud and Sergio Urzua.
[snip]
. . . The standard model developed by Gary Becker and Nigel Tomes implicitly assumes that early and late childhood investments are perfect substitutes, that one can make up later for what disadvantaged families neglect early. They also assume a single market skill.
For the study of early childhood investments, these are bad assumptions. First, skills are multiple in nature. A proper accounting of human skills recognizes both cognitive and noncognitive skills. Second, investments raise the stock of later skills through self-productivity and complementarity. Early advantages reinforce each other through self-productivity and complementarity, reducing the cost of future learning. Because of these life-cycle dynamics, the substitution between early and late investments in children is low. The most economically efficient way to remediate the disadvantage caused by adverse family environments is to invest in children when they are young.
We have found that for severely disadvantaged children, there are no levels of later childhood skill investments that can bring the children to a level of social and economic performance attainable from well-targeted early investments. We find that both social and emotional skills are essential in producing successful people. These findings change the way economists think about the human capital formation process.
If we don't provide disadvantaged young children with the proper environments to foster cognitive and noncognitive skills, we'll create a class of people without such skills, without motivation, without the ability to contribute to the larger society nearly as much as they could if they'd been properly nurtured from an early age. Neglecting the early years creates an underclass that is arguably growing in the United States. The family is the major source of human inequality in American society.
[snip]
Most macroeconomists think of human capital as education, measured by years of school. Or if they're a little more sophisticated, they measure human capital by test scores like IQ or an achievement test. Neglected are all the noncognitive abilities that are produced by healthy families. Deficiencies in these skills can be partially remediated, as we know from the early intervention programs. Not completely remediated, but certainly gaps can be closed. The things we used to think of as soft and fuzzy have a real effect on behavior.
[snip]
If a child starts out with low levels of cognitive and noncognitive ability, it becomes much less profitable to invest in the young adult. That's the notion of complementarity. If a child has a low level of ability at age 17, then productivity of investment in that person is much lower than it is in somebody who has ability and motivation. The major contributors to the college-going gap by child family income class have to do with child ability. Richer families are much more likely to send their kids to college, but once one conditions on the ability of the child at age 17, virtually all of the income effect goes away. It's all about the ability that's embodied in the child from a lifetime of early investments. So families play a huge role, but it's in making the kid college-ready. It's human ability, or rather, abilities. This is one place where Adam Smith was wrong, actually. He has a passage in The Wealth of Nations which I used to believe and used to quote in classes. And then I realized that Smith was dead wrong.
Region: As well as dead; he won't be able to respond to your critique.
Heckman: You're quite right. [Laughter] Dimitriy Masterov and I actually visited his tomb last year in Edinburgh, where we presented our work on Scottish skill formation.
But anyway, Smith says people are basically born the same and at age 8 one can't really see much difference among them. But then starting at age 8, 9, 10, they pursue different fields, they specialize and they diverge. In his mind, the butcher and the lawyer and the journalist and the professor and the mechanic, all are basically the same person at age 8.
This is wrong. IQ is basically formed by age 8, and there are huge differences in IQ among people. Smith was right that people specialize after 8, but they started specializing before 8. On the early formation of human skill, I think Smith was wrong, although he was right about many other things. And Dimitriy and I said that in the speeches we gave while in Scotland last year. We wanted to be a little titillating. But I think these observations on human skill formation are exactly why the job training programs aren't working in the United States and why many remediation programs directed toward disadvantaged young adults are so ineffective. And that's why the distinction between cognitive and noncognitive skill is so important, because a lot of the problem with children from disadvantaged homes is their values, attitudes and motivations.
Cognitive skills such as IQ can't really be changed much after ages 8 to 10. But with noncognitive skills there's much more malleability. That's the point I was making earlier when talking about the prefrontal cortex. It remains fluid and adaptable until the early 20s. That's why adolescent mentoring programs are as effective as they are. Take a 13-year-old. You're not going to raise the IQ of a 13-year-old, but you can talk the 13-year-old out of dropping out of school. Up to a point you can provide surrogate parenting.
So, coming back to job training and other interventions targeted toward disadvantaged adolescents, mainstream discussions miss the basic economics of the skill formation process. When we understand how that works, that skills build on each other, it's very common-sensical. It's not just IQ, or achievement measured by a test. That's very hard for many economists to understand. There are interactions among IQ, cognitive ability as measured by an achievement test and noncognitive ability.
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