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Nature 422, 814-815 (24 April 2003) | doi:10.1038/422814a

The writing on the slate

Andrew Berry1

BOOK REVIEWEDNature via Nurture: Genes, Experience and What Makes Us Human

by Matt Ridley


Fourth Estate: 2003. 320 pp. £18.99
HarperCollins: 2003. $25.95

The writing on the slate

ILLUSTRATION BY DAVID NEWTON

Is who we are determined ineluctably by our biological inheritance or, more malleably, by our experience? The debate is surely as old as human consciousness. In 1874 Francis Galton gave it its modern identity when, borrowing from Shakespeare's villain Caliban, "a devil, a born devil, on whose nature nurture can never stick", he cast the issue in terms of what he called a "convenient jingle of words": nature and nurture.

Having made the distinction, in Hereditary Genius Galton then set the tone for the debate to come by hewing dogmatically to an extreme position: "I have no patience with the hypothesis occasionally expressed, and often implied, especially in tales written to teach children to be good, that babies are born pretty much alike, and that the sole agencies in creating differences between boy and boy, and man and man, are steady application and moral effort. It is in the most unqualified manner that I object to pretensions of natural equality."

The other extreme has also attracted its own inflexible adherents, most notably members of the 'behaviourist' school founded by J. B. Watson, whom Ridley quotes: "Give me a dozen healthy infants, well-formed, and my own specified world to bring them up in and I'll guarantee to take any one at random and train him to become any type of specialist I might select: doctor, lawyer, artist, merchant-chief, and yes, even beggar-man and thief, regardless of his talents, penchants, tendencies, abilities, vocations, and race of his ancestors."

This polarization remains with us to this day: the debate is typically couched in terms of nature versus nurture, implying that these factors are mutually exclusive. The issue is clouded by the difficulty of bringing conclusive evidence to bear. Experiments on humans are impracticable or unethical, although the Moghul emperor Akbar, unfettered by regulations on the use of human experimental subjects, did apparently raise several individuals in total isolation to determine which religion — Hinduism, Islam or Christianity — they would spontaneously embrace. The experiment was inconclusive: the lack of stimulation during their development turned Akbar's unfortunate human guinea-pigs into deaf mutes.

Modern commentators have struggled to extricate themselves from the straitjacket of Galton's dichotomy. Some genes do indeed act independently of the environment: regardless of my lifestyle or where I live, I will inevitably develop Huntington's disease if I carry the disease-causing mutation. And conversely, plenty of our behaviour is largely environmentally determined — that I speak English, not Turkish, is simply a reflection of where I was raised and by whom. But not all behaviour resides at one or other end of the spectrum: genes and the environment often interact such that the either/or categorization of the 'versus' view is misleading.

However, as the evolutionary biologist David Sloan Wilson pointed out in the New York Times on 25 February 2003, the rhetorical allure of the extremes remains strong: "Everyone calls themselves an interactionist. Yet often, when you scratch below the surface, you find a sociobiologist who marginalizes the importance of culture, or a social constructivist who hates the very idea of sociobiology, and they end up painting caricatures of each other. True integrative thinking is in the very early stages."

Nature via Nurture is a book-length exercise in 'integrative thinking': science writer Matt Ridley has produced a paean to interaction that will do much to erode the mutually exclusive view of nature and nurture.

Interaction is best exemplified in a simple idea that typically makes an appearance somewhere near the beginning of a genetics textbook and is then ignored throughout the rest of the book: the outcome produced by a gene may depend upon the context in which the gene is expressed. Citing new work by Darlene Francis at Emory University in Atlanta, Ridley provides an extraordinary and elegant example. C57 and BALB strains of mice differ discretely in some aspects of adult behaviour. But C57 embryos transplanted to BALB uteri and raised by BALB mothers display, as adults, aspects of BALB behaviour; mere cross-fostering (C57 to BALB parent) after birth, however, does not provoke the change, implying that the uterine environment is the critical context. The C57 genotype expresses C57-typical behaviour only after development in a C57 uterus.

Ridley's historical tour of several disciplines is a delight: the pivotal players in ethology, neurobiology, anthropology and psychology are brought to life in engaging pen-portraits. We encounter anthropologist Franz Boas in 1884 during his first field season among the Inuit of Baffin Island as he notes in his diary: "These are the 'savages' whose lives are supposed to be worth nothing compared with a civilized European. I do not believe that we, if living under the same conditions, would be so willing to work or be so cheerful and happy." Konrad Lorenz appears both in his best-remembered guise, pursued by a string of adoring ducklings, and in an altogether more sinister one. While working as a military psychologist in Poland in 1942, Lorenz participated in SS-sponsored research designed to distinguish between inferior Polish and superior German characteristics in 'half-breeds'. Nor does J. B. Watson of behaviourism fame fare too well in retrospect: his fall from grace was occasioned by an extramarital love affair, and he ended up, appropriately enough, applying his skills in pavlovian conditioning to advertising Johnson's baby powder. The human detail enriches Nature via Nurture, but Ridley by no means subscribes to the modern dumb-it-down school of science writing, in which the science itself becomes a sideshow to the serious business of prying into the scientists' personal lives.

Ridley's book reminds us of the importance of good science writing. Because he is not a professional scientist, Ridley is not stuck deep in a disciplinary trench and has the freedom to range across huge swathes of intellectual territory. In doing so, he has given us a rich overview and a compellingly integrated picture of a great deal of science, both old and new. Make Nature via Nurture part of your nurture.

  1. Andrew Berry is at the Museum of Comparative Zoology, Harvard University, 26 Oxford Street, Cambridge, Massachusetts 02138, USA.