Better to go to bed lonely than to wake up guilty

Tim Lewens

  • BuyDeceit and Self-Deception: Fooling Yourself the Better to Fool Others by Robert Trivers
    Penguin, 416 pp, £10.99, January, ISBN 978 0 14 101991 8

What do we learn about the human mind from evolutionary theorising? One might think that evolutionary psychology is predominantly a backward-looking science that sketches the historical processes that led to specific aspects of the way we reason. But most evolutionists think their investigations have a forward-looking dimension too: they argue that pinning down the social and ecological demands made on our ancestors can help us to characterise more accurately what our minds are like right now.

Darwin presented the process of natural selection as a sort of ersatz creator. He thought one of the great triumphs of his theory lay in its ability to give transmutationists – those who thought species were modified versions of their ancestors – a good answer to the question of how the adaptation (or ‘co-adaptation’, as Darwin sometimes referred to it) of organic means to ends came about. Earlier natural theologians – including William Paley, whom Darwin read closely – had argued instead for the creationist view that only an intervening intelligence could explain the fittedness of eyes, wings and so on to their offices. Paley’s version of the design argument took organic adaptation to be decisive evidence for the existence of a benevolent overseer. British biologists have often portrayed Darwin as having refuted the conclusion of the argument from design, without challenging its premises. Nature may be well designed, much as Darwin’s creationist predecessors thought, but good design doesn’t require a designer. Thus John Maynard Smith once defined biological adaptations as the sorts of trait that natural theologians would have mistaken as evidence for the creator; and it is the reason Richard Dawkins, while gleefully stamping all over the nonsense spouted by intelligent-design creationists, nevertheless spends much of his time marvelling at the cleverness of specific bits of natural engineering, even referring to natural selection as a watchmaker (if a blind one), and to himself as a ‘neo-Paleyist’. Many biologists, indeed, still praise Paley for his descriptions of natural phenomena, and some continue to favour an approach that closely mirrors Paley’s: if you want to figure out how nature works, begin by asking how an intelligent engineer might have set it up.

If natural selection simply emulates intelligent design, we might wonder why evolutionists would be any better than natural theologians at figuring out how our minds and bodies work, though it has to be acknowledged that creationists are hopeless at telling us what processes led to their working as well as they do. The solution to this puzzle – part of it, at least – lies in an important difference in perspective. For the evolutionist, adaptation is born of competitive struggle: where the creationist sees the relationship between species as one of beneficent harmony, the evolutionist is instead primed to see conflict, mutually inflicted disadvantage and strategic manipulation.

The contrast between these two views is perhaps brought out most clearly in Robert Trivers’s seminal article from 1974 on the conflict between parents and offspring. A natural theologian is likely to assume that parents and their developing offspring are engaged in a largely harmonious project, directed at the efficient production of a new autonomous life. For the evolutionist, things are different. Trivers pointed out that a parent’s reproductive interests are best served by apportioning resources more or less equally between offspring, on the grounds that parents are related equally to all of their children. Any given child’s reproductive interests, however, are best served by inducing the parent to give it a disproportionately large share of resources. Important evidence of this sort of effect comes from David Haig’s work on the struggle between mother and foetus during pregnancy. Haig argues that foetal genes are selected to take more than maternal genes are selected to give. The result – borne out in many empirical studies – is a series of otherwise baffling biochemical and anatomical measures and countermeasures, in which each side attempts to shift the balance towards its own optimal interests regarding blood supply and nutrients. For example, pregnant women secrete more insulin than usual (in their own interests, as it decreases the foetus’s share of blood sugar) at the same time as they become more resistant to its effects (in the foetus’s interests, increasing its share).

The moral here is that evolutionary thinking allows us to formulate hypotheses we would have been less likely to have considered otherwise. This doesn’t mean all these hypotheses will turn out to be true. Nor does it mean that only an evolutionist could have formulated them: Haig notes that in the late 19th and early 20th centuries pathologists were already describing the maternal/foetal relationship as a ‘battlefield’. Even so, the way evolutionary thinking alerts us to the possibility of misaligned interests and strategic manipulation helps us to see how, in principle, a Darwinian might attend to aspects of human nature to which other disciplines are blind.

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