Eugenics Laboratory Lectures number 6: Pearson, Karl. 1910. Nature and Nurture, the Problem of the Future (London: Dulau and Co.). 31 pp. Based on Presidential address delivered on 28 April 1910, annual meeting of the Social and Political Education League. GLNE reprint is ‘Second edition’ 1910.
Summary
Delivered by Karl Pearson, F.R.S., in April 1910 as a Presidential Address to the Social and Political Education League, this lecture advocates for the application of exact science to social reform. Pearson emphasizes that social problems should not be solved by “general theories of society,” “verbal discussions,” or biased opinions from “fashionable medical consultant[s],” but only by observation, measurement, and rigorous analysis.
The core of the lecture is the quantitative demonstration of the overwhelming primacy of Nature (heredity) over Nurture (environment). Using the Calculus of Correlation (a number between 0 and 1), Pearson presents extensive evidence demonstrating the strength of the hereditary factor. The mean correlation for Nature (resemblance between close relatives for physical, pathological, and mental characters) is consistently high, reaching approximately 0.50 to 0.52. Conversely, the mean correlation for Nurture (association between environmental factors like sanitation, clothing, or parental habits and child characteristics) is shown to be extremely small, averaging about 0.03.
Pearson argues that if the dependence of the child on its ancestry is ten times as intense as its dependence on its environment, social reform must prioritize biological laws. He provides pedigrees illustrating how defects like congenital cataract and epilepsy persist through generations, underscoring the enduring power of heredity. He warns that the great battle-cries of social parties will increasingly turn on this problem of Nature versus Nurture, urging educational leaders to instill scientific method in their working-class audiences.
Changes Across Editions:
The lecture, originally published in 1910, was reissued in a Second Edition (c. 1912). The source material confirms that the 1910 address drew attention to the earlier Lecture Series III: The Relative Strength of Nurture and Nature, stating that it contained a fuller statistical treatment. The reissuance served to solidify Pearson’s defense of the metrical approach against rising popular and political reliance on sentiment and environmental fixes. The 1912 Second Edition would have maintained the crucial distinction between the average Nature value ($\approx 0.50$) and the average Nurture value ($\approx 0.03$), reinforcing the statistical basis for the claim that “Nature for man is more important than nurture”.
Eugenics Laboratory Lectures number 6
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