But Man, though he is Nature’s most favored child, was not constructed by her on any new principle. He is only among her many marvels…and in the structure of his mind, as in his body, there are no elements and no principles that she has not used again and again in those less exalted achievements which we call the animals.

William McDougall

A R Wallace, in his Contributions To The Theory Of Natural Selection (1870), asserts its all sufficient power to explain the evolution of life forms (with one notable exception). No organs, markings, peculiarities of instinct or habit can exist unless useful to the individuals or species which possess them, Wallace maintains.

According to Professor August Weismann, likewise, an organ or faculty that is of no survival value for any given species will degenerate, for individuals who do not possess the organs or faculties in question will still be able to survive and reproduce themselves. Weismann called this process of universal crossing ‘panmixia’ (see Weismann, Essays upon Heredity and Kindred Biological Problems, 1891-1892).

A corollary of the theory usually referred to as neo-Darwinism is the impossibility of the inheritance of acquired characters, because of what Weismann termed the ‘continuity of the germ-plasm’.

Adherence to this version of Darwinism, purified of its Lamarckian elements, lead Wallace, for one, into spiritualism. For primitive man, in his estimation, had possessed certain ‘useless’ characteristics, namely: upright posture, over-sized brain, over-developed hand, well-developed speech organs, all of which had been surplus to requirements in his environment. And some that were positively harmful, namely: lack of body hair and absence of prehensile feet (see Wallace, Darwinism, 1889).

Wallace was unable also to account for the development of man’s artistic and mathematical abilities in terms of the enhancement by natural selection of rudimentary talents shared with other life forms. To the incredulity of his fellow naturalists, he proposed that a superior intelligence (to which matter is ultimately subordinate) must have prepared primitive man for life in civilised society.

The origin and function of human psychological traits which, before 1859, were generally considered sui generis, a particular mark of the benevolence of the creator, continues to exercise the intellects of contemporary Darwinians. Their titular head is Professor John Maynard Smith, one time student of J B S Haldane and the doyen of evolutionary biology. Since 1994, the Darwin Seminar, organised at the LSE by Helena Cronin, has become a forum for the development of ‘evolutionary psychology’. Its exponents aim to revolutionise our understanding of criminology, psychiatry and moral philosophy (amongst other disciplines) by placing them all on a strict Darwinian foundation. Richard Dawkins and Matt Ridley are associated with this daring intellectual enterprise. Both have read papers to the Darwin Seminar.

Darwinism has all the hallmarks of a secular theodicy, even providing an explanation for why we die. For the death of the individual, Professor Weismann once laconically observed, is not a primary necessity but an adaptation, i.e. a product of evolution. The body of the unicellular organisms (monoplastides) and also of the undifferentiated multicellular organisms (homoplastides) is potentially immortal, barring accidents. In the scale of life, death is first encountered as a regular occurrence amongst differentiated multicellular organisms (heteroplastides) which contain only one immortal element, the reproductive cell. Weismann anticipated the characterisation of the individual as an expendable vehicle for transmitting the germ-plasm, in Richard Dawkins’ The Selfish Gene.

The current generation of Darwinians is no less adept at teasing out the reason for universal elements of human experience, generally regarded as unconscionable. Of all the essays in The Maladapted Mind (the compilation of readings under review) the most fascinating, in this context, are those which explain the major mental disorders, in particular depression, by means of the theory of natural selection.

Randolph Nesse (of the University of Michigan Medical School, Department of Psychiatry), for one, thinks we should abandon the benighted conception that depression and anxiety are malign manifestations whose abolition by pharmacology is long overdue (see his contribution to The Maladapted Mind entitled ‘Are mental disorders diseases?’).

Only a limited proportion of mental illness is due to inherited brain abnormality, in Nesse’s opinion. We should view the most widespread mental disorders not as pathologies but as something akin to bodily defenses such as fever and cough. Anxiety is useful, however unpleasant, an indispensable part of the organism’s survival system and too little anxiety ought really to be classified as a mental disorder. (The psychologist William McDougall, in his Outline Of Psychology, 1923, points out why fear is instinctive). Nesse suspects that certain probably universal fears such as that of darkness, of leaving home (agoraphobia), of flying etc are atavisms, eminently explicable in relation to the main threats in our primitive ancestor’s environment.

‘Are Mental Disorders Diseases?’ contains the paradoxical suggestion that many ‘…of the genes that predispose to mental disorders are likely to have fitness benefits…’. The universality of the capacity for sadness indicates that it must be adaptive in some way. For natural selection cares not a jot about our comfort (unless conducive to reproduction), only our fitness. The negative emotions all too familiar to sufferers from depression and anxiety are no less functional than pain or vomiting. Just as fatigue has evolved to protect us from overexertion, ‘…the capacity for sadness may have evolved to prevent additional losses’. Depression often leads us to abandon maladaptive strategies and behaviour. It also tends to elicit help and sympathy. Another contributor to The Maladapted Mind contends that depression is a strategy of submission to dominants.

Possessing the unique distinction amongst psychiatrists of wishing to make some individuals more anxious and sad, Dr Nesse (whose thought processes are uncomfortably reminiscent of Dr Strangelove) even thinks that the genes which cause manic depression must be useful. Perhaps they are linked with creativity, or cause other beneficial effects in those who do not develop the actual disorder. Schizophrenics will doubtless be gratified to learn that the genes which (allegedly) cause their disorder may confer advantages in combination with other genes.

Can ‘evolutionary psychology’ account for psychopathy (a barbarous neologism) and sociopathy? Psychopathy… But I find I have suddenly slipped off Simon Baron-Cohen’s tripod, which I borrowed for this occasion (apologies to T H Huxley for ‘maladapting’ his conclusion to ‘Agnosticism’). Those whose ‘instinct of curiosity’ has been aroused must find out for themselves, by purchasing this fascinating volume.

Leslie Jones