The Greg Clark Symposium

Earlier I wrote “Greg Clark may well be the most important social scientist of the 21st century.” Thus, the symposium in Econ Journal Watch on Clark’s new but perhaps not forthcoming book is very welcome. The symposium includes serious critics, most notably Stuhler and Benning, but I suspect even the critics would agree with Arden and Plomin who write:

We agree wholeheartedly with Clark’s overall message that genetics accounts for outcomes long assumed to be due to nurture. Like other books in his trilogy, Clark marshals evidence from diverse sources to support his argument. The data reach in this book—1600–2026—is jaw-dropping. Clark (and his colleague Neil Cummins) turned to wedding-register marks, probate courts, Huguenot wills, Oxbridge matriculation rolls, Sandhurst cadet lists, Wedgwood servants, and the Guild of One-Name Studies, to name a few. These data are imaginative, arresting, and inspiring. The analyses conducted, given the manifest complexities of harmonising across data types, time, and place, are impressive. …This audacious scholarly book properly lights a fire under important questions. We look forward to following the work, its critics, and its rebuttals. It’s a terrific scientific contribution; because it is so thoroughly interdisciplinary, it will enrich and enliven the conversation about social status, its causes, and malleability.

One thing I am struck with from the critics (not just those in the symposium) is that most acknowledge that twin and adoption studies have badly undermined the claim that parental investments are big determinants of adult ability and earnings. The critics are correct that more elaborate environmental models can reproduce genetic-looking correlations but keeping an environmental explanation alive is not the same as vindicating the explanation people originally believed. Clark and many others have pushed the debate far into new territory.

There is also a basic asymmetry between the competing explanations. Genetics supplies independently established inheritance rules. When an environmental model reproduces the same patterns by choosing transmission rules precisely because they mimic genetic inheritance, it is accommodating the evidence, not independently predicting it. True, Clark also requires some free parameter choices, but he is clear that these can and need to be independently estimated.

The kinds of parental effects being demonstrated also matter. The nurture effects the environmentalists point to often seem to be for optional, steerable, or transferable choices than for more fundamental abilities, that is, changing what a child chooses to do with a given set of abilities, versus changing those abilities. Parents, for example, have more influence over religious identification than over religiosity, more influence over wealth than income, more influence over educational attainment than IQ.

The genetic arguments in the book draw the most criticism and yet the book has much else offer as Clark notes. For example:

Social status is inherited as strongly as height. Even relatives as distant as nine generations apart, 270 years, still show significant correlation in social status.

That is a very striking finding–especially given the intervening industrial revolution, multiple wars, huge changes in social mores etc.–but if it stands, it does so independent of the genetic explanation.

The fact that this monumental and challenging book–right or wrong–cannot find a major academic publisher is an intellectual scandal. The editors at Princeton University Press and the University of Chicago Press should be ashamed.

Addendum: See previous MR posts on Clark including Tyler’s Conversation.

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