When Gould meets Galton

A.W.F. Edwards

  • The Mismeasure of Man by Stephen Jay Gould
    Norton, 352 pp, £9.95, May 1982, ISBN 0 393 01489 4

Modern evolutionary biology seems prone to idle argument and useless controversy, as if it had an urge to experience once again the exciting atmosphere of the Darwinists v. the Creationists, or the Mendelians v. the Biometricians; or perhaps a longing to experience the ecstasy of the physicist, the Maxwell or the Einstein, whose new theory so splendidly and triumphantly succeeds. The trouble probably stems from the fact that the really successful theories of biology in recent decades have been biochemical and molecular, leaving the natural historian who tries to move from a specific area of study to the construction of general hypotheses with little to argue about. So the population geneticists set to with fierce debate about whether the majority of mutations are neutral in their selective effect, the taxonomists classify themselves as cladists or evolutionary systematists and hurl insults at each other, and the evolutionary biologists split into sociobiologists and the rest – separate species, we may suppose, since intercourse between the two has not so far proved fruitful.

Stephen Gould’s contribution to this last debate is to open one or two coffins containing the scientific skeletons of the past with the purpose of nailing down the lids even more securely. From the point of view of the modern debate, they were better left undisturbed, but The Mismeasure of Man is fine history, and relevant to the present-day controversy insofar as it explains its social background: for example, I now appreciate far better than hitherto why it is that Americans, in particular, argue so passionately (and so rarely dispassionately) about IQ testing.

The first half of The Mismeasure of Man chronicles 19th-century anthropometry, especially craniometry, and the naive conclusions that were sometimes reached. It is not difficult to do a demolition job in this field, and Gould revels in it, examining the corpses in macabre detail. Did you know that some enthusiast actually got hold of Gauss’s brain and found it to weigh 1492 grams?

Gould submits some of the old data to a crushing re-examination, though – without wishing to condone the views to which the erroneous conclusions led – I myself incline to a more charitable view of those involved. They were caught up in the revolutionary introduction of statistical procedures into biological thinking, and not only were the available methods primitive, but, as Galton was quick to point out, they had been developed in the physical sciences where the statistical ‘error’ was something whose very existence was to be regretted and which the methods therefore sought to eliminate, whilst in the biological sciences the ‘error’ was the very variability under study. The same mathematics underlay different models: to the physicist, the Normal curve is a distribution of observational error; to the biologist, it is a distribution describing the variate under study – height, weight, even brain size.

It is indeed when Gould meets Galton that the reader first detects a prejudice on the part of the author. The section is headed ‘Francis Galton – apostle of quantification’, and it is worth giving almost in its entirety (save for the quotations from Galton, indicated by dots):

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