Evolutionary psychology Evolving theories of behaviour

VER a relatively short period of time evolutionary psychology O has become a prominent way of understanding the human mind and behaviour. Its origins lie in a number of JOHN ARCHER describes a rich research agenda for theoretical analyses of animal behaviour in the 1960s and early 1970s which evolutionary psychology in testing novel hypotheses. transformed the way this subject was studied and understood. Just as the often provide new ways of viewing existing discipline at the time. Conventional social evolutionary approach led ethologists phenomena, and therefore aid overall psychology assumes that human behaviour away from concentrating on the immediate understanding of psychological can be explained in terms of culture-specific causal mechanisms controlling animal phenomena, but the speculations social learning, with relatively little behaviour, so evolutionary psychology themselves may be difficult to test contribution from evolved dispositions seeks to lead conventional psychologists empirically. to act in particular ways. In contrast, away from explanations that concentrate These considerations apply to one evolutionary psychology involves thinking only on immediate mechanisms and mental strand of evolutionary thinking, that about human beings in ways that generate events. Instead it offers a single unifying concerned with the origins of present-day novel testable hypotheses that would have starting point for understanding why we behaviour, and its original adaptive been beyond the scope of conventional think and behave as we do today: natural significance. Consideration of adaptive social science thinking (provocatively selection has made us this way. significance is (as the pioneering ethologist referred to as the SSSM or standard social This simple statement hides a number Niko Tinbergen (1963) pointed out) science model by Tooby & Cosmides, 1992). of complexities that need to be understood a different type of explanation from that There would have been no reason for before the powerful insight can be involving immediate causal mechanisms, a conventional social psychologist working translated into an effective research agenda. which is the concern of most psychologists, within the SSSM to have thought that In this article I deal with two of these whether traditional or evolutionary. stepchildren should be at any greater risk complexities that often lead to Evolutionary psychologists tend to than natural children for child abuse or misunderstandings both within and outside combine evolutionary biology’s emphasis homicide; that the relatives of new-borns the evolutionary perspective. They are, on ultimate or functional explanations, with should comment disproportionately on the first, how specific evolutionary hypotheses psychology’s emphasis on the immediate infant’s resemblance to the father rather are derived from broader evolutionary causes of human behaviour. The way the than the mother; that a man’s degree of principles, and second, the limitations of two are linked is expressed in phrases such bodily symmetry would have any impact the assumption that human behaviour is as ‘the past explains the present’ (Tooby & on his sexual attractiveness; that human adaptive in an evolutionary sense. Cosmides, 1990, p.375), or ‘we are sexual psychology is influenced by sperm walking archives of ancestral wisdom’ competition; and that the ratio of the length Origins and mechanisms (Cronin, 1991, p.3). The connection is also of the second and fourth digit is related to One common dismissive view of seen in the principle referred to as ‘reverse musical ability. But these are among the evolutionary psychology is that it engineering’ of a particular trait or often counter-intuitive hypotheses that have represents a series of just-so stories based disposition (Pinker, 1997) Ð using present- been generated by an evolutionary on imaginary scenarios of Stone Age life. day construction to reveal the adaptive approach to human social life. This is a misconception, but it is one that significance. There are, therefore, two major is based on the self-evident truth that we By viewing present-day mechanisms as contributions of the evolutionary approach. cannot know the precise circumstances reflections of past adaptations, novel ways It provides informed speculations about the under which the human species evolved, or of looking at human behaviour are evolutionary origins of human behaviour, the social organisation of early hominids. generated, along with testable hypotheses and generates novel testable hypotheses Instead informed speculations are based on about present-day dispositions and the about current psychological mechanisms. various types of indirect evidence, notably mechanisms controlling them. Just as the Although the first is useful for an overall broad evolutionary principles, cross-species scope of social scientific inquiry is understanding of psychological comparisons, cross-cultural surveys, and constrained by its sociopolitical context, phenomena, it is the second that is present-day human behaviour. These so too is it constrained by the ideas that are important for establishing evolutionary informed speculations about origins can generated by the shared assumptions in the psychology as a research-based discipline.

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A hierarchy of hypotheses Buss did not explain his fourth- or ones, or where it was older females who Critics of the evolutionary psychology lowest-level hypotheses in any detail, committed most violent acts. We would programme often confuse what is being but from the example in his diagram not expect men and women to be equally tested in empirical studies. Particular data they would appear to apply to even more discriminating or indiscriminate about their sets are viewed as supporting or refuting specific circumstances, and to involve choice of a sexual partner. All of these the ‘evolutionary approach’. They do not. further additional assumptions to those of could in principle occur if human They support specific hypotheses drawn the third level. An example provided by behaviour had been shaped only by the from evolutionary or non-evolutionary Buss was that women have evolved dictates of cultural and historical forces. views of human behaviour. preferences for men who are high in status. But such behaviour is rarely Ð if ever Ð This important distinction can be This is not a hypothesis that is directly observed even at the individual level. clarified in relation to the notion of derived from Trivers’s parental investment We note the saintly and other-worldly a hierarchy of levels of analysis involved theory, as is the impact of paternity character of people of a religious calling in evolutionary hypothesis testing (Buss, uncertainty on male sexual jealousy. who turn their backs on both their families 1990). At the top is the principle of natural Instead it is derived from the principle of origin and their future marriage selection, which informs the whole of that where males are likely to contribute prospects. The idea of gangs of elderly modern evolutionary thinking. This is not resources and time to child rearing, females female delinquents only exists in the bizarre being tested in specific studies, since it is should choose those males that show signs minds of Monty Python scriptwriters. The well-established as a mechanism for the of being able to do so. Buss has translated reality is that we can derive a fairly detailed generation of adaptive changes over time, this general principle into a specific picture about what to expect of the social and can only be assessed by considering hypothesis applying to the human case, life of humans from the knowledge that we a wide range of biological and geological which is that women should be attracted are mammals that have evolved through the evidence that has accumulated over the last to men with money and status. That many process of natural selection (Brown, 1991). two centuries. women are so attracted is not disputed, but Most of the research agenda of The next level down in the hierarchy whether this is a consequence of evolved evolutionary psychology involves levels of consists of broad principles governing the adaptations, or a pragmatic decision in theorising and hypothesis generation that evolution of social behaviour, such as kin societies where men control access to are removed in some way from these selection (Hamilton, 1964), reciprocal resources, is a matter of dispute (e.g. Buss, general principles. They involve additional altruism (Trivers, 1971), and the parental 1989; Eagly & Wood, 1999; Hrdy, 1997). assumptions, and can be regarded as third- investment theory of sexual selection The important point about this debate is or fourth-level evolutionary hypotheses in (Trivers, 1972). So it is proposed that that if the consensus of the evidence does Buss’s scheme. I have already referred to behaviour can be governed by a need to support the alternative non-evolutionary two examples, male sexual jealousy and help relatives and those who have given explanation, this will have falsified one women’s preference for high-status men, help, and mates are chosen on the basis particular lower-level evolutionarily- which involve applying general principles of the effort they will put into bringing up derived hypothesis, rather than the higher- derived from sexual selection theory to offspring. Again, these broad principles are level principle it originated from. specific circumstances that (particularly not being tested in individual studies since in the second example) entail a number the evidence supporting them comes from Implications of other considerations and assumptions. a wide range of comparative studies of One implication of this hierarchical view To explain what is being tested in such animal behaviour, so that data derived from of evolutionarily derived hypotheses is that cases we can consider the example of a single species such as our own would be evolutionary psychology can serve several internal fertilisation leading to paternity too narrow in scope. purposes. At the level of the higher-order uncertainty. When associated with paternal How these second-level principles hypotheses it can tell us in a general way care, this should lead to adaptations to operate in different species of animal or what we should expect human behaviour maximise the males’ chances of caring for under different environmental conditions to be like if it were indeed the product of their own offspring rather than those of requires us to take into account further, natural selection, and if general principles unrelated males. It is important to more specific, influences. For example, such as kin selection, sexual selection and recognise that this is a general principle, since human beings have a long gestation reciprocal altruism do apply to our species. derived from the principle of sexual period within the female’s body, internal Many of the broad generalisations about selection (Trivers, 1972). It does not inform fertilisation, and poor infant survival human behaviour that we take for granted us about the specific forms these without the efforts of two parents, these are in line with these principles; for adaptations will take, only that we should considerations can be used to generate example the importance of kin in human expect to find some. Thus any particular specific Ð or third level Ð hypotheses about social interactions, age and sex differences test of a suggested adaptation for making what to expect under these conditions. One in violence, the importance of reciprocity paternity certain will not disprove the influential inference is that this will lead to in social interactions between unrelated overall principle were it to yield null male sexual jealousy and proprietary individuals, and the link between sexual results. If there were, for example, tests controlling tendencies by men to their attractiveness, reproductive capacity and of five such possible adaptations that all female partners (e.g. Daly & Wilson, 1988; health. produced null results, we would have Buss et al., 1992). However, this is not the We would not therefore expect to find grounds for beginning to doubt the validity only inference that could be made from the a human society where people helped of the overall principle. We would have to reproductive circumstances applying to unrelated individuals in preference to close look again at the extent to which modern humans (Hazan & Diamond, 2000; Miller kin, where old, sick people were found to sexual selection theory (from which the & Fishkin, 1997). be more attractive than younger healthy principle was derived) applied to the

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human case. bodily symmetry and traits associated with appear to be out of place. Predators and In practice several mechanisms for aiding fitness, the alternatives become less likely. prey, and parasites and hosts, are in a paternity certainty have been suggested, in However, the bottom line is that even if the constant evolutionary arms race. One will particular that men become more upset by the bulk of the evidence were inconsistent with often be ahead of the other, thus rendering thought of sexual infidelity in the absence of the predictions, we would only be the other’s adaptations obsolete. A reed emotional infidelity whereas women are more eliminating hypotheses about specific warbler’s parenting response to a cuckoo upset by the thought of emotional infidelity in proximal cues, not the underlying chick is maladaptive, yet it occurs despite the absence of sexual infidelity, and that men evolutionary principle that a healthy selection pressures for the parent to show controlling behaviour towards their genotype and attractiveness are linked. recognise the parasitic eggs and throw mates to a greater degree than do women. These examples illustrate the nature them out of the nest. Its parenting response These two mechanisms have been of research hypotheses in evolutionary has not been refined by natural selection to investigated in a number of studies that have psychology: they are concerned with the take account of the current environment, generally produced evidence for their type of psychological mechanisms that one that contains the social parasite. There existence (e.g. Buunk et al., 1996; Regalski & might underlie certain evolutionary is evidence that heavier selection pressure Gaulin, 1993; Weiderman & Kendall, 1999). principles, rather than being tests of the over longer time periods does result in This example indicates that although principles themselves. This does not more discrimination in the parenting the broad functional principle is clear, the diminish the value of evolutionary response (Davies & Brooke, 1988). precise mechanism through which it hypotheses, which have generated a large In the human case the difference operates is not necessarily so, and has to be amount of research from a different between the African savannah where our investigated by setting up and testing more vantage point than that of conventional species spent its formative years and the specific hypotheses. A second example can psychology. It does, however, highlight present-day Western world is enormous. further illustrate this point. A broad a fundamental misconception about Gone are the immediate threats to survival evolutionary principle is that sexual attraction evolutionary psychological research, that in posed by predators, food shortage, infectious should have evolved to preferentially each case ‘the evolutionary view’ is being disease and extremes of temperature. discriminate those individuals with tested. Rather it is a specific hypothesis Indeed our hominid ancestors would hardly qualities that enable better chances of derived from evolutionary principles, but recognise today’s environment as the same surviving and reproducing copies of their which almost certainly involves a number planet. When each of us enters the modern genes. The mechanisms that operate to of additional (lower-level) assumptions. world we bring with us bodies and brains produce such ends will again be varied, and adapted to solving problems encountered in several researchers have suggested specific Adaptation, non-adaptation another way of life. The short time during hypotheses. Singh (1995) argued that the and maladaptation which humans have transformed their important cue that indicates a person’s Does a Darwinian framework mean that environment has been too short for new reproductive condition and health is their all human behaviour is adaptive? In the patterns of behaviour better fitted for the waist-to-hip ratio, and that this is a examples considered so far, the assumption modern world to have evolved. Thus many particularly potent cue for male attraction was made that we were considering current non-adaptive responses can be to women. Several researchers (e.g. features that were (and are still) adaptive viewed in the context of the modern Gangestad & Thornhill, 1997; Manning, for the individuals concerned, that they transformation of the human environment. 1995; Thornhill & Gangestad, 1999) have would have conferred survival and Consider the case of physical aggression investigated bodily symmetry, and argued reproductive advantages. This is certainly between young men. It is widely recognised that it indicates developmental stability appropriate where we are considering that as a consequence of sexual selection, (arising from a phenotype that will aspects of social behaviour associated with fighting in the animal world is more common withstand environmental disruptions and sexual selection, since the characteristics of and has more damaging consequences stresses during development). the environment for which they are adapted among males in breeding condition than Consequently it will act as a marker for (i.e. other people) have changed little since among other age and sex categories ‘good genes’ in a prospective mate. early hominid times. But if we take a wider (Darwin, 1871; Trivers, 1972). This is also Again, the reasoning here involves look at human behaviour, it is clear that the case for the human species. But several hypotheses concerning the sorts of there are important aspects that convey no features have combined in some modern mechanism that will effectively undertake fitness advantages in the modern world. environments to make physical aggression the tasks that an evolutionary principle has This applies particularly Ð but not between young men potentially even more identified as needing doing. However, it is exclusively Ð to behaviour viewed as dangerous and maladaptive to those always possible that these particular pathological (Gilbert, 1998). concerned. These features include alcohol hypotheses are not the right ones. Singh Some maladaptive human reactions can and guns. In different ways they bypass the could be mistaken in believing that waist- clearly be identified as having had fitness evolved rules that apply to animal conflicts to-hip ratio is the universal feature that advantages throughout evolutionary history. (Archer, 1988, 1994; Archer & signifies good reproductive health. Male A ‘sweet tooth’ is adaptive when sugar is Huntingford, 1994). attraction to it could be, as the findings relatively rare, but not in present conditions Animals engage in an escalating series of Yu and Shepard (1998) suggest, a when sweet foods are constantly available. of threat displays before deciding whether culturally learned response. Alternatively, The fight-and-flight response is adaptive to attack or retreat from a potential opponent. symmetry could be linked with some other for responding actively to predators, but In doing so they are assessing the other’s feature related to attractiveness. But as not when trapped in a traffic jam. Yet it is fighting ability relative to their own, and more and more research supports both not only the human environment that can this will guide their decision whether to Singh’s hypothesis and the links between change at such a pace that adaptations pursue the conflict. This is a strategy of

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self-interest, of not picking a fight when conditions. We can look to several general have combined to produce a set of the signs are that it will be lost, which is principles to understand why non-adaptive reactions to the death of loved-one which particularly important for animals with or maladaptive features may result from are not in themselves adaptive. However, dangerous weapons. Fights between red natural selection. These include the they represent a trade-off with the wider deer stags provide a good example restricted starting points natural selection functional utility of attachment and (Clutton-Brock et al., 1982). They first use has to operate on, trade-offs between separation mechanisms. the opponent’s size to assess fighting competing demands, and the incorporation Ethologists are used to finding examples ability. If there is no obvious difference in into mechanisms of simple ‘rules of of simple mechanisms that operate well size, the protagonists roar, which is a more thumb’ that are effective under most but enough in the conditions under which the sensitive indicator of fighting ability. If this not all circumstances. I will now look at animal usually finds itself, but which can does not settle the dispute by one examples of these principles in turn. easily form maladaptive responses under withdrawing, they move to a parallel walk, Considering the first of these principles, other conditions. Such responses, which in which contact with the antlers is invited. natural selection operates on an already operate on the basis of a simple ‘rule of Even when contact begins, the animals formed organism. This situation leads to thumb’, are generally associated with push with their antlers rather than using the considerable restrictions and compromises animals possessing simple nervous systems. more dangerous points to stab the other. in what is possible, producing many design The occurrence of ‘social releasers’ Ð Men do not possess dangerous natural flaws. Human anatomy provides several stereotyped reactions to simple sets of weapons such as antlers, or even the canine examples, such as the crossing over of the stimuli in the social world Ð serve well teeth found in chimpanzees. There has digestive and respiratory tracts, resulting in enough to ensure that animals show therefore been less selection for elaborate the dangers of choking, and the design of aggressive, sexual and parenting reactions and cautious build-ups to physical fights. the human spine, which is not best suited under the appropriate conditions most of the Nevertheless, it is clear from studies of bar- for bipedalism (Gilbert, 1998). time. They enable ethologists to trick the room fights that men do appraise one Grief provides an example of the trade- animal into making the same response to another prior to engaging in physical off between adaptive and maladaptive inappropriate circumstances in experimental aggression (Benson & Archer, 2001; features. This series of emotional, mental situations Ð for example, a male stickleback Graham & Wells, 2000). One of the several and behavioural reactions to loss is will attack models placed in its territory as influences of alcohol seems to be to cause associated with a number of features long as they possess a red underside, even people to overestimate their own abilities that can lead to physical ill health and though otherwise they look unlike a real relative to those of opponents, and behaviour that would compromise the fish (Tinbergen, 1948, 1951). But social therefore enter into fights with opponents survival and reproductive prospects of the releasers also enable other species to who are likely to beat them (Archer, 1994; individual (Archer, 1999, 2000). Since practise similar ‘deception’, as in the case Benson & Archer, 2001). grief occurs in all known human societies, of the reed warbler’s response to cuckoo Guns have been referred to as the great and in other social mammals and birds, it chicks referred to above. equaliser. Their use obviously bypasses any would seem to be a process that has Although human behaviour is usually appraisal of the other’s fighting ability, so resulted from natural selection. How considered to operate on the basis of far that evolved rules count for nothing. A man this occurred in spite of its non-adaptive more sophisticated decision processes than can lose a fist-fight, leave the scene of the features represents a further challenge for these, this is not always the case. Lorenz fight, and return with a gun to shoot the evolutionary psychologists. (1950/1971) applied the concept of social winner. This is precisely the scenario Some have responded to this challenge releasers to human parenting responses, behind many cases of male on male by seeking to find ways in which it might noting that a set of features common to the homicide in contemporary United States prove adaptive despite first appearances; for young of most bird and mammal species (Daly & Wilson, 1988). example that it evokes help or sympathy form a common basis for the human The example of assessment of fighting (e.g. Crawford, 1989; Izard, 1991), or that it parenting responses. The implications of ability shows how two features of the provides a signal to the individual to change this view, which has received support from contemporary human environment, drinking its behaviour (Nesse, 2000). subsequent empirical studies (Archer, alcohol and possessing firearms, have Following Bowlby (1980), and Parkes 1992), is that the human response to infant bypassed rules and signals that have evolved (1972), I suggested that the maladaptive features is based on a simple rule of thumb. consistently throughout the animal kingdom. features of grief represent trade-offs with It can therefore easily be diverted to Alcohol causes individuals to overestimate adaptive mechanisms for ensuring the inappropriate circumstances where the their fighting ability and firearms render persistence of important social bonds same infantile features (such as big eyes any assessment worthless. This is an despite separations (Archer, 1999, 2000). and pouchy cheeks) occur in an individual interesting example in which an evolutionary For this to happen there must be stable that is not a human infant, such as a stuffed approach, based on the study of animal internal representations of significant toy (Hinde & Barden, 1985) or a cartoon fighting, can serve to illuminate the human others that are continually checked with the character (Gould, 1980). These case yet falls short of a complete analysis, outside world. These produce relationships considerations can explain at least the which has to take account of the impact of that endure even when the other is not initial attraction for many humans of dogs the changed environment, of culture and there, and that motivate separation or cats possessing infantile features. Over technology, on evolved behaviour. reactions. The stability of the time, this can lead to strong attachments to In contrast to this example there are representations, the widespread occurrence them, attachments that are maladaptive in some aspects of human behaviour that of separation reactions compared with evolutionary terms (Archer, 1997). have never been adaptive, whether on the death, and the relative recency in human The three principles outlined in this African savannah or under modern urban evolution of the understanding of death, section provide different ways in which

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aspects of human behaviour have come differences in homicide (that they view as specific mechanisms or cues through which to depart from the assumption that all a non-adaptive feature) as an indication of more general adaptive principles operate. behaviour produced by natural selection is individual differences in tendencies towards The second issue concerned limitations to adaptive. They provide complications for escalated physical aggression (an adaptive the assumption that current human an empirical analysis of human behaviour feature). By the same reasoning, individual behaviour is adaptive. based on evolutionary principles, but they differences in humans’ positive reactions to Although there are many important do not necessarily limit it. pets (a non-adaptive feature) should follow examples of non-adaptive or maladaptive Non-adaptive aspects of human behaviour their individual differences in positive human behaviour, this does not necessarily that are byproducts of other, adaptive, forms reactions to human babies (an adaptive limit the application of evolutionary of behaviour can still provide important feature). principles to these topics. Current human sources of evolutionary hypotheses, providing dispositions that are non-adaptive or that they show consistent variation in relation Conclusions maladaptive are often linked in a consistent to that adaptive feature. Thus individual In this article I have considered two way with adaptive responses, and can differences in grief (a non-adaptive feature) issues with important implications for therefore be used as indirect measures of vary in relation to the strength of attachment understanding the research agenda of these adaptive reactions. (an adaptive feature), and provide the basis evolutionary psychology. The first was the for an evolutionary programme of empirical nature of the specific hypotheses derived Professor John Archer is at the investigations into individual differences in from general evolutionary principles, that Department of Psychology, University of grief (Archer, 1999, 2001). Similarly, Daly they always involve additional assumptions, Central Lancashire, Preston PR1 2HE. and Wilson (1988) have used individual and that they are generally concerned with E-mail: [email protected].

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RCHER has provided an important service in laying out A very clearly just what is involved in evolutionary psychology’s research agenda. This is important both because every discipline should be asking what it can learn from every other discipline and Peer commentary by ROBIN DUNBAR. because the evolutionary programme is so often Ð I am tempted to add, wilfully Ð evolutionary considerations (namely complex. We tend to do science by misunderstood. I want to emphasise this in fitness, or more crudely the desire to controlling confounding variables in order what follows, along with another important have grandchildren). Obviously there are to expose the one key variable we are point raised by Archer: that evolutionary a number of proximate goal states that are interested in to systematic manipulation. psychology is itself divided into a number involved (the basic drives perhaps) but But in biological systems it is extremely (at least two, some say three) very different these are simply essential stepping stones common for one variable to be traded off research agendas that focus on very on the way to maximising fitness. against another. The classic trade-off in different kinds of questions. The simple truth is that dead men biology is that between parental care and So, let me begin with the question of neither tell tales nor reproduce, so we can litter size. I can choose (if I may be misunderstandings. Evolutionary approaches expect evolution to produce a motivational pardoned for using conventional biological to human behaviour have repeatedly come system that is designed to avoid situations terminology here) to have lots of offspring under attack over the years, mainly because that are likely to result in death. But within but invest nothing in them (in which case, they have been interpreted as implying that these general constraints, most advanced many will die before they get to human behaviour is genetically determined organisms (those with brains of sufficient reproduce), or I can have few offspring and so cannot be changed Ð or that if we size to do the computations) are left by and invest nurturingly in each (so can show that all the many rather nasty evolution to figure out for themselves the increasing each one’s chances of surviving things we do to each other are evolved best way of achieving these deep goal to reproduce). (Salmon and humans are behaviours, this means that they are states according to the circumstances of the specific examples of these two strategies, justified and ‘good’. This argument has moment. It would be almost impossible to by the way.) There will always be a point nothing to do with biology or evolution: do otherwise, since the contingencies of in the two-dimensional state space where is does not mean ought. real life (especially for long-lived species) the two strategies produce equal numbers But there is another reason why this are such that no amount of advance of surviving offspring. This is because time claim is nonsense, and this is that no programming could possibly produce (or energy) constraints invariably make it species is so constrained in its behaviour. an organism capable of responding impossible to achieve both goals (of Such an argument would imply absolute appropriately to every single contingency. quantity and quality of offspring) at the genetic determinism in the strong sense, Experience and smartness must play same time in biological systems. If we but most biologists would be surprised if crucial roles. focus on just one variable, we will be you could demonstrate that anything above The important conclusion here is misled into thinking that some individuals the amoeba is that genetically determined that the evolutionary approach focuses on are doing very badly. in its behaviour. The reality is that all strategic decision making, not on genes as The suggestion that organisms species (but not humans, critics of the the determinants of behaviour. The maximise under constraint leads us directly evolutionary approach would apparently assumption is that the goal states involved into the second issue, namely the fact that lead us to believe!) are extraordinarily are fitness-related, and it is an empirical there are interesting evolutionary questions flexible in their behaviour. To be sure, they question how well humans (or any other to be asked about the cognitive machinery have species-typical limits to this flexibility species) match up to performance of the that supports these kinds of decision (pigs really don’t fly). But within those rational fitness-maximiser. On the whole, making (at least in those cases where limits their behaviour is determined much the data suggest that humans (like most meaningful choices between behavioural more by the contingencies of the world: other animals) are generally pretty good at options are being made). The kind of animals respond to the costs and benefits of it. This is not to say that some individuals approach I outlined above does not concern the choices that face them, and we can alter don’t make mistakes. Mistakes are an itself with the cognitive machinery; it simply their behaviour quite easily by changing essential part of the evolutionary process Ð assumes that, so long as we can show that the relative weightings of those costs and there would be no evolution without them. things work properly at the behavioural benefits. If this sounds like good-old familiar The claim is simply that organisms get it level, there must be something in the black learning theory, you’re not too far wrong! right on average, and that means some do box that does the relevant work. This In other words the evolutionary better and others do worse. approach tends to focus on behaviour and approach merely argues that organisms in But there is another reason why tries to measure behavioural outputs as general (humans included) are guided by mistakes should occur Ð and this is that indices of fitness (numbers of babies goal states that are, ultimately, dictated by the biological world is extraordinarily produced, how much energy or wealth is

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invested in individual offspring, who leaves not in any way conflict with functional (or Professor Robin Dunbar is with the what to whom in their will). This tradition indeed developmental) questions. Evolutionary Psychology Research Group, concentrates on what Tinbergen identified It is important to appreciate that even School of Biological Sciences, University of as functional (or purposeful) questions. In though some evolutionary psychologists Liverpool, Nicholson Building, Liverpool many ways, this approach is nothing more focus on one approach to the exclusion of L69 3BX. Tel: 0151 794 5917; e-mail: than social psychology in a new guise: it is the other, they are not mutually exclusive. [email protected]. concerned principally with people’s Many labs that work on human relationships with each other. evolutionary psychology (including my But the question of what cognitive own) do both kinds of study with equal processes are involved in all this is enthusiasm. Indeed we should view the genuinely interesting. Is the human mind evolutionary approach as a genuine designed to be sensitive to certain kinds of opportunity to weld together the cues? Is the human mind designed to innumerable cracks that threaten to tear respond to those cues in certain kinds of psychology as a unitary discipline apart. ways? What constraints does the machinery If you like, the evolutionary approach of the mind impose on our decision- shows why cognitive psychologists and making flexibility? These questions require neuropsychologists (with their interests us to use the conventional cognitive in mechanisms) should take social psychology toolkit of carefully designed psychology (which needs a more functional pencil-and-paper tests. These questions orientation) seriously Ð and vice versa. concern mechanistic explanations, and do

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August 2001 The Psychologist Vol 14 No 8 Evolutionary psychology Main agendas and hidden agendas VOLUTIONARY psychology has a growing appeal, Archer begins. E As rhetoricians know, repackaging cliché as new insight threatened by conservative critics rarely fails to seduce. Are attractive young women alluring? Males randy? Step-parents wicked? Men Peer commentary by LYNNE SEGAL. competitive? Women nurturing? Let us generate some ‘novel testable hypotheses’. of our (genetically dormant) DNA Ð so hypotheses today? Its simplicity may Did I hear ‘novel’? No, grandpa, lie back assiduously mapped these last two decades. appeal to the media’s inevitable populism and snooze. We are busy deploying science Although a seasoned critic of the (we are what our Stone Age ancestors in the service of your favourite tunes Ð conceptual confusions and quantitative made us), its alleged biological trappings ‘Birds do it…’. fetishism of experimental psychology, may consummate some psychologists’ Before flux and uncertainty rocked I can suggest a few testable hypotheses of dream that their discipline reduces to truths physics early last century, the dream of my own. They are not unconnected to my of the natural sciences (‘culture is part of science was that the material world could personal and political agenda, easy to our biology’), but its scientific credentials be tracked back to its foundations, and the fathom, however recently unfashionable. have always been the object of rigorous laws of mathematics and physics combined These hypotheses are not so novel, having rebuttal from authoritative critics directly to produce readily falsifiable predictions. already been tested in the UK. They engaged with the complexities of human This remains evolutionary psychology’s concern the behaviour of human females genetics. Why are we discussing the promise to a discipline long frightened in relation to issues of ‘reproductive recycling of suspect science long after its of failing tests of rigorous predictability Ð advantage’. Grandpa, wake up; I know weaknesses have been repeatedly exposed? well after many scientists accepted you are worried! One reason is the reassurance it offers in ‘the disorder of things’ (Dupré, 1993), The main supposed ‘truth’ of the face of human malleability, particularly embracing greater epistemic diversity. evolutionary psychology is that all living the cautionary tales it carries for the sex Archer offers ‘a single unifying starting creatures are driven to maximise the which has recently broken down many of point for understanding why we think and successful reproduction of offspring, with the social injustices of the past: read any behave as we do today: natural selection male and females exhibiting contrasting of Helena Cronin’s pronouncements that has made us this way’. behaviour patterns owing to their opposed enhancing women’s financial independence Yes, the human species evolved and has (low versus high) ‘parental’ investments. is at odds with human nature (e.g. Cronin survived; but natural selection has made us Let’s test it. Do women in Britain act in & Curry, 1996). what way, exactly? The search is on for line with ‘reproductive advantage’? Are But there is more to it than this, universals of human behaviour. Yet, Archer women more likely to have children when especially the genetic boosterism admits, should we claim to find they are most vigorous and fertile? Do encouraged by over-funded molecular behavioural universals, this would hardly women delay having children while biologists in search of human genetic establish the validity of any conjectured waiting for men with resources? Do blueprints. However, those wishing to do evolutionary origins. He fails to add that women with children remain with males justice to Darwin himself note that for him talk of evolutionary selection is empty who support their biological offspring? evolution was never narrowly, or even speculation unless psychologists offer Here are some answers. In the UK in the primarily, a biological affair. It was rather evidence, as Darwin did, of the natural 1990s, women overall delayed giving birth a slow, heterogeneous, profoundly history of their presumed evolved until their thirties. The proportion of environmental process. ‘Alas, poor behaviour Ð appearing or disappearing as women remaining childless increased Darwin’, as many distinguished researchers adaptations to specific local conditions. steadily over recent decades. The number (ranging from molecular biology to They do not. of single and lone mothers has expanded developmental psychology) lament in the Meanwhile, off the agenda is all that rapidly since 1970. More women cohabit latest scholarly rebuttal of evolutionary is uniquely human: the starting point for and marry later; more divorce and separate psychology (Rose & Rose, 2000). These anyone interested in the historical (HMSO, 1995). Neo-Darwinians meet are researchers who see their labours temporalities and spatial diversities of women freer to decide how they want to mocked by the pseudo-scientific posturing human lives, or the cultural formations in live (although rarely in conditions of their of evolutionary psychology, since the which they are lived. These could hardly be own choosing). complexity of our evolutionary history less uniform; nor more unlike those of even Why select evolutionary psychology (with its barely understood genetic the great apes, with whom we share most as the standpoint from which to formulate unfoldings) produces no certain biological

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outcomes. Talk of the biological origins of offer no data to suggest that the genes of References human existence neither explains any men who rape have been selected for over Dupré, J. (1993). The disorder of things. Cambridge, MA. particular pattern of events nor predicts men who do not, nor to support their calls Harvard University Press. their future direction. for more modest dress in women. Cronin, H., & Curry, O. (1996).What next? 10 big We can all play the correlational game I could go on supplying this kind of challenges from the evolutionary agenda. In J. Ashworth, H. Cronin & O. Curry (Eds.), Matters of life of ‘testable hypotheses’, as in Daly and critique. The main point is that and death:The world view from evolutionary psychology. Wilson’s use of ‘kin selection’ to ‘predict’ evolutionary psychology’s unifying Demos Quarterly no. 10. London: Demos. men’s violence, and children’s presumptions bear no relation to growing HMSO (1995). Social focus on women. London: HMSO. susceptibility to murder or abuse from step- genetic knowledge Ð which all suggests the Rose, H. & Rose, S. (Eds.). (2000). Alas poor Darwin: parents. They cannot explain why many unpredictable complexities in human Arguments against evolutionary psychology. London: Jonathan Cape. people adopt children, and usually take genetic transactions. Trying to understand Thornhill, R., & Palmer, C. (2000). The natural history of rape: loving care of them. They cannot predict even rare genetically ‘simple’ diseases, like Biological bases of sexual coercion. Cambridge, MA: MIT why violence against wives often begins haemophilia, proves hugely complicated. Press. when the woman is pregnant, cannot be What millions of years of genetic change impregnated by ‘rival males’ and carries have actually produced is the potential for 50 per cent of her aggressor’s genes Ð the human cultural invention. It is ironic if, in most home-bound and submissive wives the name of science, psychologists merely (like foreign brides) being most at risk of find new ways of recycling old forms of murder. Similarly, Thornhill and Palmer’s reductionism. recently hyped ‘rape-adaptation hypothesis’ flies in the face of statistics on the Lynne Segal is Anniversary Professor of frequency of male-on-male rape, rape Psychology and Gender Studies, Birkbeck without penile penetration, the sexual abuse College, Malet Street, London WC1E 7HX. of pre-pubescent girls and the infrequency Tel: 020 7631 6069; e-mail: of rape resulting in conception. [email protected]. Characteristically, Thornhill and Palmer

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August 2001 The Psychologist Vol 14 No 8 Evolutionary psychology The design of the human mind HE central goal of psychology is to understand the complex design T of the human mind. Evolutionary psychology is founded on the premise that conceptual tools emerging from modern evolutionary theory can aid in this noble quest. That humans have evolved is Peer commentary by DAVID M. BUSS. uncontroversial. That humans owe the design of their bodies to evolutionary predictions derived fail to be supported same-sex rivals (Schmitt & Buss, in press). processes is uncontroversial. That the 1400 empirically, then the hypotheses can be People are also faced with the problem that cubic centimetre brain and its functional rejected on scientific grounds alone, as their mates might find other partners who mechanisms have evolved is some have; if they are formulated precisely are more desirable, and hence be tempted uncontroversial. What remains contentious, and confirmed empirically, then they can to have an affair or to leave the and legitimately so, is precisely how be accepted on scientific grounds alone, relationship. Given the magnitude of evolutionary processes have sculpted the as some have (Buss, 1999). investment that people expend on selecting psychological mechanisms housed in that This article highlights an often and attracting mates, it would be large brain. overlooked dimension of evolutionary astonishing if selection failed to fashion Among scientists who have grappled psychology Ð its heuristic value in guiding psychological mechanisms designed to with evolution and human behaviour there researchers to important domains of prevent rivals from poaching and mates is disagreement about the relative inquiry that have been ignored by more from defecting (Buss, 2000). importance of various evolutionary traditional approaches to psychological Evolutionary biologists have discovered processes such as natural selection, sexual science. One scientist captured this an extraordinary array of mate-guarding selection, and genetic drift (Dawkins, 1982; contribution as follows: Darwinism merely mechanisms among male insects and Gould, 1991). There is also disagreement ‘provides a guide and prevents certain animals. These range from sequestering the about the centrality of adaptations as kinds of errors, raises suspicions of certain female, remaining physically attached to opposed to by-products of adaptations explanations or observations, suggests the female after copulation, emitting scents (sometimes called ‘exaptations’; see Buss certain lines of research to be followed, and to counteract the attractant signals of the et al., 1998; Gould, 1991; Pinker, 1997). provides a sound criterion for recognizing female, reducing the conspicuousness of But there are no known scientific significant observations on natural the courtship display, physically repelling alternatives to the premise that evolutionary phenomena’ (Lloyd, 1979, p.18). other males, building a fence around the processes are responsible for creating One realm of human behaviour entirely female, and inserting a mating plug in the human psychological mechanisms, overlooked before evolutionary female reproductive tract (Thornhill & whatever their nature turns out to be. psychologists came along was the domain Alcock, 1983). Traditional psychologists, Evolutionary psychology differs from most of ‘mate guarding’ (Buss, 2000). The however, had never thought to examine perspectives in psychology by attempting theory of sexual selection (Darwin, 1871) mate guarding in humans. No mainstream to confront this premise explicitly. has guided researchers to the centrality of psychological theories had guided Archer highlights two ways in same-sex competition or intra-sexual researchers to this potentially important which evolutionary thinking can aid the rivalry in the mating arena. In sexually domain of inquiry. understanding of human behaviour Ð as reproducing species, members of each sex Once exploration began, guided by a way of informing theories of human are in competition with members of their evolutionary thinking, many fascinating origins and as a means of generating novel own sex for mating opportunities. phenomena were discovered. Nineteen hypotheses about evolved psychological Adaptations can evolve through the two distinct human mate-guarding tactics have mechanisms. Contributions of this type are component processes of sexual selection been documented, ranging from vigilance worthy, although they are often met with Ð preferential mate choice for certain to violence (Buss, 2000). Researchers strident rejection and unseemly attacks on qualities, and competition among members discovered that women and men alike the motivation and character of scientists of one sex for access to the opposite sex. guard their mates, but they use somewhat who propose them. However, there is no To pick one example, gaining a mate different tactics in doing so. Men are more reason to summarily jettison an important does not solve the adaptive problem of likely than women to attempt to conceal source of novel hypotheses about the retaining a mate. Since desirable mates their mates, display resources to prevent human mind. If the proponents fail to often remain attractive to others after they their mates from leaving, threaten rivals formulate the hypotheses in a precise are mated, people are faced with the verbally as well as nonverbally (e.g. the and testable manner, or if the derived adaptive problem of ‘mate poaching’ from cold primate stare), and physically attack

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The Psychologist Vol 14 No 8 August 2001 rivals who attempt to encroach on their The key point is that conceptual to believe that strong reactions will mates. Contrary to stereotypes, men are tools drawn from evolutionary theory have subside. Hopefully, the debate can be also more likely to display submission served an important heuristic function for elevated to a rational examination of merits and self-abasement in the service of mate psychologists. They have guided on scientific grounds rather than shrill retention, for example promising to change researchers to domains previously rejection on emotional grounds. The or going along with everything the mate neglected by more mainstream science of psychology can ill afford to requests. Women are more likely than men psychologists, such as the domain of discard a theoretical perspective that has to repel rivals by publicly displaying human mate guarding. They have informed proved its worth among thousands of non- commitment. The statements ‘I told the the articulation of hypotheses in this human species. There is no reason to other women how much we were in love’ domain. And they have led to the discovery believe that humans are magically exempt and ‘I wore his clothes in front of others’ of important phenomena that were from the causal processes that have shaped illustrate this tactic. Women also take previously unknown in the psychological all forms of life. Evolutionary psychology greater pains to enhance their physical literature. provides conceptual tools for helping with attractiveness in the service of mate Evolutionary perspectives on human the complex endeavour of discovering the retention. behaviour have generated outrage and design of the human mind. Researchers have also discovered debate ever since Darwin articulated his a key set of circumstances that predict the theory of natural selection in 1859. Dr David M. Buss is Professor of amount of effort a person will devote to A contemporary of Darwin was reputed Psychology at the University of Texas, solving the adaptive problem of mate to have said: ‘Let’s hope that it’s not true; Department of Psychology, Austin, Texas guarding (Buss, 2000). The most important but if it is true, let’s hope that it doesn’t 78731, USA. E-mail: predictors of men’s mate-guarding effort become widely known.’ There is no reason [email protected]. are the perceived probability that the partner will kiss, date or have sex with Buss, D. M., & Shackelford,T. K. Issues, 47, 43–65. other men; the mate’s physical References Buss, D. M. (1999). Evolutionary (1997). From vigilance to Lloyd, J. E. (1979). Mating behaviour attractiveness; and the magnitude of age psychology:The new science of the violence: Mate retention tactics and natural selection. The disparity between the members of the mind. New York: Oxford in married couples. Journal of Florida Entomologist, 62, 17–34. couple. The strongest predictors of University Press. Personality and Social Psychology, Pinker, S. (1997). Evolutionary women’s mate retention efforts are the Buss, D. M. (2000). The dangerous 72, 346–361. psychology:An exchange. New husband’s income and the amount of effort passion:Why jealousy is as Darwin, C. (1871). The descent of York Review of Books, XLIV, necessary as love and sex. man and selection in relation to 55–56. the husband devotes to getting ahead in the London: Bloomsbury. sex. London: Murray. Schmitt, D. P,& Buss, D. M. (in press). status hierarchy (Buss & Shackelford, Buss, D. M., Haselton, M., Dawkins, R. (1982). The extended Human mate poaching. Journal 1997). Some of these findings are Shackelford,T. K., Bleske,A., & phenotype. San Francisco:W. H. of Personality and Social Psychology. intuitively obvious, others not so obvious Wakefield, J. (1998). Freeman. Thornhill, R., & Alcock, J. (1983). The (e.g. men’s use of submission in mate Adaptations, exaptations, and Gould, S. J. (1991). Exaptation:A evolution of insect mating systems. retention). spandrels. American Psychologist, crucial tool for evolutionary Cambridge, MA: Harvard 53, 533–548. psychology. Journal of Social University Press.

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RCHER’S clear account of the feasibility and necessity of testing A evolutionary psychological hypotheses follows in the footsteps of a series of articles making the same point, the most recent being Ketelaar and Ellis (2000). It seems to need constant repeating Peer commentary by ANNE CAMPBELL. that all hypotheses, from whatever theoretical position they are derived, are arrive at the place where the real academic features). no more than ‘just-so’ stories until they debates occur. An evolutionary prediction, Other reasons why adaptations appear are subjected to empirical test. Hypotheses for example that men should everywhere less-than-perfectly tailored to their concerning the mental algorithms used by and at all times show higher levels of intra- problem-solving role include the lag time humans to solve longstanding adaptive sexual aggression than women (as a between adaptive problems and solutions problems are no exception. function of their greater fitness variance), (we are more prone to snake phobia than A reasonable hypothesis Ð given the is often appropriated by alternative non- gun phobia despite the latter’s far more advantages of biparental care and the fact evolutionary positions and argued to flow common and lethal quality), local optima that internal fertilisation creates paternity from culturally acquired gender roles. Such (where a better adaptation may exist but uncertainty Ð would be that men should theorists accept that evolution has been cannot be reached from our current state have evolved the ability to detect ovulation responsible for a human ability to acquire without temporarily and catastrophically in women. But they clearly have not. This culture, but not for its contents. sacrificing fitness), lack of sufficient suggests that the problem of paternal But these ‘proximal’ accounts evade genetic variability on which selection can uncertainty has been solved in some other the questions of why such gender-bound work (X-ray vision could well be way, and Archer offers a number of patterns in aggression occur across all advantageous but no human possesses even empirically supported solutions. Candidates cultures so far examined; why they are the rudimentary capability of extending for human adaptations are identifiable by evident across a wide variety of measures; their spectral sensitivity this far) and costs their species typicality, evidence of special why they manifest themselves prior to that we would be happier without design, untutored emergence, resistance to acquisition of gender identity and are not (testosterone effectively matures the male modification and ancestral fitness benefits. a function of differential parental sexual system but compromises the The challenge for evolutionary socialisation; why they peak at precisely immune system leading to earlier male psychologists is not merely to locate them the age when men are most preoccupied senescence and death, which, because it but to specify how these modules operate Ð with sexual access to females; why they occurs post-reproductively, escapes what inputs they accept and what continue to be as apparent in both self selective elimination). contingent outputs they generate. It is ratings and gender stereotypes today as in The point is that adaptations do not unfortunate that psychology’s the 1950s despite massive changes in roles; have to be optimal Ð they need only preoccupation with proximal mechanisms and why they are visible in all other generate behaviour that is better than that (the how question, which evolutionary species with greater female parental of our competitors. As the old joke about psychologists also address) has created investment and are modulated by early the two men running from the bear so aptly a climate where consideration of the androgen exposure (Campbell, in press). captures it Ð First man: ‘You’ll never ancillary question of origins and functions I would like to expand on Archer’s outrun him’. Second man: ‘I don’t have to. (the why question) is viewed with discussion of constraints on optimal I just have to outrun you’. suspicion. adaptations (see Buss et al., 1998). He With regard to Archer’s phrasing of the But the why question is central since discusses three in detail: forced design question ‘Does a Darwinian framework it distinguishes evolutionary hypotheses moves (blood vessels running across the mean that all human behaviour is about adaptations from alternative surface of the retina would be considered adaptive?’ it is worth noting that not even explanations that view the origins of a classic example of poor design if an the most ardent Darwinian believes that all human behaviour as culturally acquired and engineer was starting from scratch); trade- human behaviour represents an adaptation. nearly infinitely malleable. When we reach offs between different systems that leave us Evolution, if it were the whole story, still the lowest level of Buss’s hierarchy Ð the with design flaws (the pain and danger of has to reckon with the existence of by- derivation and testing of specific human childbirth resulting from the intense products and random effects (Buss et al., predictions about the form that adapted pressure toward bipedalism); and adaptive 1998). Just as light bulbs incidentally give solutions to recurrent evolutionary systems that can misfire (e.g. Disney’s off heat though they were designed to problems might take among humans Ð we exploitation of our response to neonatal provide light, so the human navel is not

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there to aid our survival or reproduction but transmitting memes or socially acquired the present and depends on the stability of is a remnant of the umbilical cord that was knowledge (e.g. specific languages and selection pressure over the next tens of necessary to supply food to us as in utero. technologies) through generations in thousands of years. These selection By-products are recognisable by their a parallel way to genetic inheritance. There pressures may be very different from those consistent link with an adaptation. But that is controversy about how just how tightly that operated in the past. The effects of does not mean that there is universal these memes are tied to the biological best natural selection have been attenuated agreement about whether a given attribute interests of the individual, but it is clear (thankfully) in many parts of the world by is an adaptation or a by-product Ð Gould that many fitness-irrelevant memes spread huge medical advances that have especially (1991) argues that the human capacity for widely. Preferences for fatness or thinness, benefited the most vulnerable Ð premature language was a by-product of large brains, for caviar or cod, for acid house, rock or infants, neonates and the elderly. which were originally selected for some sitars all affect human behaviour but there The effects of sexual selection have other unspecified function. In addition, is no assertion that they are adaptive. been altered recently by the demographic natural selection does not screen out noise It is also important to bear in mind that transition Ð an evolutionarily novel state or random effects. These are chance ‘adaptive’ is distinct in meaning from both in which the tie between resources and fluctuations, independent of adaptations, ‘useful’ and ‘adapted’. Many currently reproductive success has been broken. that neither enhance nor detract from useful behaviours are not adaptations. As far as the shape of our adapted future is fitness. They are superficial modifications, Literacy is a very handy tool but it is concerned, we will just have to wait and let at least from the point of view of natural too recent a faculty for selection to have our genes find out through the eyes of our selection. Take individual differences in worked upon it; hence young humans descendants. personality Ð since we retain a normal require considerable tutoring to master it. distribution of extraverts and introverts However, if those individuals who find Dr Anne Campbell is a reader in the there is no reason to suppose that variation reading simple were to prove more Department of Psychology University of on this trait is important for natural or attractive mates and so produce more Durham, South Road, Durham DH1 3LE. sexual section. If it were, the favoured offspring than others (and if the selection Tel: 0191 374 2615; e-mail: value would have gone to fixation. pressure was consistently directional and [email protected]. But human behaviour is also influenced long-lasting), the ability to acquire reading by culture and, contrary to some critics, swiftly could be positively selected in the References evolutionary theorists do not ignore this future (Miller, 2000). Buss, D. M., Haselton, M. G., Shackelford,T. K., Bleske,A., L. fact. Fitness-relevant aspects of culture are To say that a behaviour (or more & Wakefield, J. C. (1998).Adaptations, exaptations and thought by most evolutionary psychologists correctly the psychological module that spandrels. American Psychologist, 53, 533–548. to be constrained by genetic evolution (as produced the behaviour) is adapted is to Campbell,A. (in press). A mind of her own:The evolutionary captured in the phrase ‘Genes hold culture say that during human evolution it psychology of women. Oxford: Oxford University Press. on a leash’). Culture is viewed as evolved conferred fitness benefits of such Dennett, D. C. (1995). Darwin’s dangerous idea.New York: individual preferences writ large, which act significance that those individuals who Simon and Schuster. as a selecting environment for genotypes. possessed it systematically survived and Gould, S. J. (1991). Exaptation:A crucial tool for evolutionary psychology. Journal of Social Issues, 47, Hence cultures everywhere encourage reproduced more effectively than those 43–65. marriage (in some form), parental who did not. Ketelaar,T., & Ellis, B. J. (2000).Are evolutionary investment, reciprocal altruism and co- Whether or not a contemporary explanations unfalsifiable? Evolutionary psychology operation, but discourage theft, violence behaviour or mental algorithm is adaptive and the Lakatosian philosophy of science. Psychological and suicide. (i.e. will result in systematic selection in Inquiry, 11, 1–21. Culture also acts as a tool for future generations) cannot be answered in Miller, G. F.(2000). The mating mind. London: Heinemann.

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August 2001 The Psychologist Vol 14 No 8 Evolutionary psychology Much ado about very little UMANS, like all other species, are evolved organisms, and like H all other multicellular animals, have complex and lengthy routes of development to maturity. So any understanding of human psychology must Peer commentary by HILARY ROSE properly take into account evolution and and STEVEN ROSE. development as well as historical social and cultural contexts. So much is fairly rapidly learn their limitations). reproduces a concept of family and kin uncontroversial. That what now passes for Elaborate evolutionary speculations add which anthropologists have for almost 30 evolutionary psychology (EP) has become, nothing. years discussed and rejected as a ‘folk as Archer suggests, a ‘prominent way of It is particularly troubling that such model’. Like Mrs Thatcher’s attacks on gay understanding the human mind and speculative accounts centre on the social and lesbian unions as ‘pretend’ families, behaviour’, fanned by a host of popular and sexual practices of our palaeolithic the folk model knows already the ‘real’ books but drawing on rather limited and ancestors (the so-called environment of family as an enduring biologically based often controversial research data, is clear. evolutionary adaptation) where data is, to relation of solidarity. Thus within EP the The question is whether it offers any useful say the least, scanty. Archer falls into the biological account of family is given additional explanatory or descriptive power standard EP error of claiming that ‘human priority over the social. Even while small in understanding the specificities of, as nature’ was fixed in this period and that children say that their pet dog is part of ‘EPers’ put it, ‘why we do what we do’. there has been insufficient time in the 6000 their family, or gay partners fight to secure To understand the problem this presents, or so subsequent generations to change it Ð legal recognition, or we read the reasoning we need to distinguish enabling from an assertion which is negated by the robust through which judges decide contestations causal mechanisms, and proximal from experimental and observational evidence of of parenthood for infants born using IVF distal explanations. That we are both the rapidity with which gene-based techniques, where the meanings of ‘to empowered and limited in our behaviours evolutionary change can occur (for this father’ and ‘to mother’ spiral into by our evolutionary history is a matter of and other elaborations of the evidence complexity, the mythic ‘real’ family common agreement Ð our psychologies and discussed in this response see Rose and constantly seeks to assert itself. our societies and cultures are patterned by Rose, 2000). Unquestionably, in everyday life this folk our long lifespan, the first period of which Archer’s defence is to retreat into model has huge power and jostles is spent in lengthy dependency on references to unspecified ‘broad alongside the other multiple concepts of caregivers. Our sensory limitations, notably evolutionary principles’ which enable family in cultural contestation. However, olfactory, constrain our worlds. These are ‘informed speculations’ to be made about the task of science is to unpick the non-trivial enabling distal generalisations. what might be expected of human complexity, not reproduce folk models. But they permit vast ranges of different behaviour. He argues that although such In deriving universal behavioural behaviours, and are of a level of generality principles are unfalsifiable they generate propositions, no ethologist would ignore that makes them relatively unhelpful in sub-hypotheses which, can be tested, the specificities of each individual species most of the specific themes (generally although even if demonstrated to be false, in terms of its sexual and offspring-rearing focused around sex, violence and selfish would not invalidate the general approach. practices. The sexual practices of behaviour) for which EP makes its pitch. So his appeal, finally, is not to empirical scorpionflies are not projected on to Proximal explanations of individual science but to metaphysics. But are the peahens and peacocks, but this changes behaviours will indeed include physiology sub-hypotheses he quotes indeed supported when EP turns its attention to the human and development, but will also take into by the evidence? animal. Here little respect is paid to the account specific social contexts. That, as One of the more disturbing conceptual empirical studies of social anthropologists, Archer suggests, men picking bar-room weaknesses in evolutionary psychology, sociologists, or for that matter quarrels size up their opponents before and replicated in Archer’s review, is the developmental neuroscientists. Instead the fighting unless drugged or drunk or in unreflective treatment of the linked sexual, infanticidal, coy practices of other, possession of guns (those ‘equalisers’) is concepts of family and kinship. EP arbitrarily selected, species are projected more usefully accounted for in terms of positions itself as a discourse between the ad lib. on to humans. The extreme individual prior experience (youngsters life and the social sciences, yet it plasticity of human behaviour Ð itself a

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product of human evolution Ð is set aside. a second rape, might well see the Thornhill commitments or non-commitments) on to When evolutionary psychologists draw and Palmer book as a third. They treat rape any live-in lover, thus shoring up their inferences from animal behaviour studies victims as on the same ontological level as distal thesis of genetic love. to human behaviour, they also neglect scorpionflies, to the biologists such victims It is important not to duck the ethical fundamental differences. To take an are just objects of research not human implications of Daly and Wilson’s thesis, example Archer does not discuss Thornhill subjects active in the understanding of their for their approach requires that the voices and Palmer’s (2000) account of rape. In the own lives. Given that this book has to be of victims are silenced. For that matter they scorpionflies Thornhill studied he was able the nadir of EP literature, it would have fail to explain the counter-evidence that to specify the negative environmental been nice to see Archer disassociate adoptive parents do rather better on the conditions under which all males forced himself from it explicitly. violence and abuse stakes than biological sex on (in his heightened anthropomorphic The example he does draw on is that of parents. The proximal explanation that the language ‘raped’) female scorpionflies. Daly and Wilson, and here it is troubling social commitment of these would-be This, Thornhill argues, is evolutionarily to find a psychologist of Archer’s status parents is what counts and not genetic love adaptive behaviour. So far so good; careful, tolerating such casual biological is ruled out by the Darwinian credo. Yet well-designed studies. Had he followed the constructions of family relationships. There again the horse of evolutionary speculation changing practice of his profession during has long been compelling Euro-American has got the explanatory bit between its the 1980s and changed the evidence that when a non-biologically teeth and shows no sign of being reined in anthropomorphic language of ‘rape’ to related man lives with a woman and her by either conflicting evidence or that of ‘forced sex’, his audience would children the incidence of sexual abuse and conceptual criticism. probably have remained among the violence is likely to be greater than where professional journal readers. However, he the biological father lives with them. Professor Hilary Rose is a sociologist is both unwilling to give up on the term, However, Daly and Wilson’s commitment at City University, London. E-mail: and is deeply committed to making the to the bio-folk model of a ‘real’ family, [email protected]. human link, however inappropriate. leads them to categorise all such men as Professor Steven Rose is Joint Thus, when Thornhill and Palmer turn ‘stepfathers’. Empirically this is ludicrous. Gresham Professor of Physic at University to rape among human beings some Imagine asking a child from such a College London, and Director of the Brain extraordinary contortions are necessary to household ‘Is that man your dad?’ What and Behaviour Research Group at the place it within an evolutionarily adaptive might Daly and Wilson do with replies Open University. E-mail: framework. First the concept of rape has to such as ‘No he’s my mum’s boyfriend, my [email protected]. be delimited, removing all the forms that dad lives two blocks away’ or ‘No he’s just cannot result in reproduction (e.g. anal my mum’s current boy friend, I haven’t got rape). In one move such victims of rape are a dad’ or even ‘Well he and my mum try to silenced, their pain is discounted. Instead pretend he is, but I don’t like him’. Daly References the biologists assure us that the suffering and Wilson clearly do not listen to what Rose, H., & Rose, S. (Eds.). (2000). Alas poor Darwin: of raped fertile-age women is the greatest. children say in all its complexity, and are Arguments against evolutionary psychology.Cape. Thornhill, R., & Palmer, C.T. (2000). A natural history of rape: Rape victims, who not infrequently thus free to impose the category of Biological bases of sexual coercion.MIT. describe the subsequent court hearings as stepfather (regardless of his emotional

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August 2001 The Psychologist Vol 14 No 8 Evolutionary psychology Do not adjust your beliefs, there is a fault in reality Why do some commentators have problems with evolutionary psychology? JOHN ARCHER responds.

HREE of the commentaries are it by censoring certain possibilities before other high-quality journals, such as Animal sympathetic to evolutionary they are tested. Behaviour and Proceedings of the Royal T psychology, the other two hostile. Of course critics of evolutionary Society, have published evolutionary These opponents perceive problems with psychology such as the Roses never use research. A large body of findings has the predictions derived from evolutionary the term censorship. They come nearest to accumulated, as evidenced by various psychology. But why is the derivation of admitting to this position when they object textbooks published on the subject. novel hypotheses so controversial? to evolutionarily based research because of The Roses’ portrayal of evolutionary Hypothesis testing is, after all, central to its presumed implications for social policy. thinking as muddled and unsound involves the scientific method. Who could possibly Attempts to discredit the scope or quality an incorrect characterisation of its disagree with it? The answer is anyone of evolutionary research, or to claim that its theoretical ideas. Near the beginning who views scientific research as theoretical basis is muddled or unsound, of their commentary, they state that it is subservient to ideological beliefs. Unlike are used as additional debating tactics. necessary to distinguish proximal from political or religious beliefs, scientific Behind the critical commentaries by distal mechanisms. In their discussion of research involves a way of deciding Segal and the Roses is the assumption that what is or is not regarded as a family by between competing explanations. It evolutionary psychology is inherently particular individuals in contemporary therefore seeks to be objective, open and reactionary, and has undesirable policy society, they forget this injunction. They accountable. Yet, since science is located implications. This exemplifies the fallacy confuse kinship Ð a distal evolutionary in the social world, it is subject to social referred to by Dunbar of confusing is and mechanism Ð with proximal mechanisms pressures derived from political and ought. There are now serious Ð in this case the evolved dispositions that religious beliefs. Suppression of considerations of the policy implications cause people to regard others as kin. The unacceptable findings and theories have of the evolutionary programme, from operation of these mechanisms leads us to occurred throughout history, but more people of various political persuasions, regard as kin those with whom we share subtle influences operate all the time even including the left (e.g. Peter Singer author our lives, be they a pet dog or gay partner, in liberal democracies. of A Darwinian Left: Politics, Evolution to use the Roses’ examples. That such non- The research agenda is limited by and Co-operation). Many female adaptive attachments occur does not detract commonly held beliefs. Certain topics are evolutionary researchers view themselves from the ultimate function of the deemed worthy of investigation, whereas as feminists, and see no conflict with mechanisms involved Ð kin recognition. others are not, or are not entertained as evolutionary analyses of human behaviour. Throughout their commentary the Roses possibilities. Thus investigation of It is surely preferable to use empirical seek to obscure the sound theoretical basis women’s issues was largely ignored in research rather than political dogma as a of EP in evolutionary biology, partly by the early part of the 20th century, owing to basis for social policy. The Roses dismiss conflating proximal and distal an unchallenged male-centred view of the Daly and Wilson’s findings on stepchildren’s explanations, but also by ignoring social world. An agenda informed by risk of abuse, accusing them of ‘silencing important evolutionary principles. Their feminist critiques became acceptable, the voices of victims’. In contrast to this discussion of kinship and family is greatly even fashionable, among Western emotive rhetoric, Daly and Wilson rely on impoverished and muddled as a result of psychologists from the 1970s onwards. logical argument and careful empirical ignoring Hamilton’s principle of kin This has enriched the subject by extending research, and have provided a great service selection. Another claim, that evolutionary the possibilities for empirical investigation, to potential victims by highlighting psychologists impose the mating patterns and introducing new ways of interpreting important risk factors. It is the Roses who of other species on humans, neglects the findings. do a disservice to victims by seeking to reality that it is broad principles, derived Likewise, evolutionary psychology has obscure important research findings, and from modern sexual selection theory, that raised novel possibilities about human hence their policy implications. usually inform evolutionary hypotheses, social behaviour, for example that it may The Roses seek to discredit the quality not isolated examples from one species. be influenced by sperm competition, or by of research in evolutionary psychology, Such attacks on the scientific quality of bodily symmetry, or by bodily secretions. claiming that the data are ‘limited and evolutionary psychology obscure the real These would have been outside the controversial’. The reality is that objection, that it provides a view of human thinking of conventional psychologists, evolutionary research is as sophisticated as behaviour that the Roses (incorrectly in my since they are not part of a world view any in psychology today, and much of it opinion) regard as being at odds with informed by culturally based explanations conforms to the rigorous standards of progressive political thinking. A paraphrase of social behaviour. However, these leading APA journals. Neither is it the case of the title of one of their articles – ‘Do not possibilities are only hypotheses to be that it is limited, since there are two adjust your beliefs, there is a fault in tested. The issue is, therefore, whether to specialist journals devoted only to reality’ Ð characterises their response to the broaden the research agenda or to narrow evolutionarily based studies, and many challenge of evolutionary psychology.

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