Sociobiology is used in both a wide and a narrow sense. As Ernst Mayr (1982:598) put it, ‘Sociobiology, broadly speaking, deals with the social behavior of organisms in the light of evolution.’ This definition would include ethology, biopolitics, primatology, behavioural zoology, eugenics, population genetics, biosocial anthropology, evolutionary ecology, and all the disciplines that accept the neo-Darwinian mandate. In the narrow sense, following the coinage of E.O. Wilson in his Sociobiology: The New Synthesis (1975), it refers to the application of theories of evolutionary genetics, stemming from the work of the modern synthesists of the 1930s and 1940s (Huxley, Haldane, Fisher, Wright) as modified by Hamilton, Williams, Maynard Smith and Trivers in the 1960s and 1970s. Here we shall explore both senses of the word.
All the sociobiological disciplines derive ultimately from Darwin’s (1859) theory of natural selection (as modified by later discoveries in genetics), differing only in their interpretations. Thus they should not be confused with so-called Social Darwinism, which was in fact derived more from Herbert Spencer’s developmental and progressive theories than from Darwin’s essentially non-progressive theory of ‘descent by modification’. In keeping with Darwin’s own approach, especially in The Descent of Man (1871) and The Expression of the Emotions in Man and Animals (1872), sociobiology maintains that humankind is part of the natural world, and that therefore human behaviour is subject to analysis by the principles of natural science. Thus it stands firmly on the side of human sciences as natural sciences, as opposed to the view of them as purely cultural sciences: in terms of the traditional debate as set by Dilthey in the 1880s, it is for Naturwissenschaft as against Geisteswissenschaft (or Kulturwissenschaft in Dilthey’s later formulation). It thus stands also in firm opposition to many current anti-positivist trends in philosophy and the social sciences and humanities. Whatever the differences among themselves, and these can be quite profound despite outside perceptions of homogeneity, the sociobiological sciences have a common aim of developing theories that apply to social behaviour in general, whether human or non-human. Human behaviour has unique qualities, but is not therefore exempt from the laws of natural selection, and even those unique qualities must be explained on its principles.
There are several strands or traditions that follow in the Darwinian tradition. One is the natural history tradition: the careful observation of the behaviour of both domestic and wild animals, birds and fish, from the lowest organisms to the higher mammals. Much of this was carried on outside the academy by dedicated amateurs, as it had been since long before Darwin. Indeed Darwin could be counted as a member of its ranks. But like the other strands, it was to receive much new impetus, and above all a working theory, from Darwinism. Whitman in the USA and Spaulding in the UK, whose work influenced William James, were followed by such notables as Lack on the robin and Fraser Darling on the red deer. During the 1930s, this observational tradition developed an academic base under Heinroth and Lorenz in Germany, Tinbergen in The Netherlands, Huxley in Britain and Alice in the USA. The academic development came to be known as ethology (a word originally coined by John Stuart Mill). (For a general summary see Eibl-Eibesfeldt’s Ethology, 1975.) Its general principle was that behaviour throughout the life cycle of an organism emerged according to an evolved programme, but a programme that needed releasers or stimuli from the environment for its completion, as in the classic case of ‘imprinting’—by young animals on their parents—for example. The environment included other organisms, and the main stress was on the communication mechanisms that evolved to make social interaction possible. After the Second World War it was joined by remarkable developments in primatology stemming from both zoology and anthropology, principally under Hall, Kummer, Washburn and the Japanese students of their indigenous macaque populations. Later Jane Goodall (under the direct influence of Louis Leakey and the investigation of human origins) was to pioneer the field study of chimpanzees, and George Schaller that of gorillas.
The involvement of anthropologists as well as the growing interest in human behaviour among the ethologists proper, led to various attempts to apply principles derived from animal behaviour studies (which continued across many species) to human behaviour (‘comparative ethology’). These involved such areas as territorialism (Ardrey), dominance hierarchies (Chance, Barkow, Chase), mother-infant bonding (Count, Harlow), male bonding, female hierarchies, optimism (Tiger), aggression (Lorenz), ritualization (Huxley), attention structure (Chance and Larsen), kinship, incest avoidance, social categories (Fox), attachment (Bowlby), facial expression (Ekman), courtship (Eibl-Eibesfeldt, Lockard), childhood behaviour (Blurton Jones, Chisholm, Konner), art (Morris, Disanayake), fathering (Mackey) and politics (Somit, Masters), to name but a few. The first general attempt at synthesis for social scientists came with Tiger and Fox’s The Imperial Animal (1971). The general attempt to use theories and methods of ethology to study human behaviour and society—either through interpretation or by direct study—came to be known as human ethology (see Fox and Fleising 1976—note that this review article considers ‘sociobiology’ a recent subfield of human ethology—and Eibl-Eibesfeldt’s definitive Human Ethology, 1989) and continues as a lively tradition, especially in Europe.
Primatology has developed almost as a separate discipline from ethology and includes field studies of primate kinship and mating, ecology, communication, politics, and the linguistic abilities of apes. Studies of captive colonies and laboratory animals, as in the work of Hinde and Harlow, for example, have been important. Because of the heavy input from anthropology and the nearness of relationship between humans and the other primates, the relevance of primate studies for the study of the evolution of human behaviour has always been central. In the spirit of comparative ethology, anthropologists have continued to examine the social life of primates for clues to the evolution of human social organization (DeVore, Wrangham, Hardy, Fox, Kinzey, etc.) Human ethology also maintains a continuing close relationship with studies of hominid evolution generally, and such developments in the neurosciences as the study of the complex relationships between hormones, neurotransmitters, and social behaviour (‘neuroethology’). The work of Chomsky and the transformational grammarians and such biolinguists as Lenneberg, for example, was important in bringing human verbal communication under the aegis of ethological interpretation, and away from the purely cultural.
Another major tradition stems from the rediscovery of Mendel and the growth of genetics. This was an independent development in its origins, but once married to Darwin’s theory of natural selection (after an initial confusing period when it was thought of as a rival to that theory: see Mayr 1982) it developed an impressive field of evolutionary population genetics which was concerned with the causes of the shifting of gene frequencies in populations over time. There was a remarkable convergence of these ideas in the 1930s which, following the title of a book by Julian Huxley (1942), has come to be known as the ‘modern synthesis’ and involved the work of among others, R.A.Fisher, J.B.S.Haldane and Sewall Wright. What the synthesis did was to marry the population concerns of the naturalists with the mathematical concerns of the geneticists and show how natural selection was the bridge. It did not, however, concern itself overly with the evolution of behaviour in the manner of the ethologists. The latter continued to operate largely under the aegis of ‘group selection’ theory, although this was often unstated. In the clear case of Wynne-Edwards in his Animal Dispersion in Relation to Social Behaviour (1962) it was central, stating that conventional behaviours evolved, for example, in order to achieve the control of populations.
During the 1960s a reaction set in to this form of thinking that was to have profound effects for the future of human behavioural evolutionary studies. Williams (1966) produced an elegant series of arguments insisting that natural selection could work only on individual organisms, not groups, and Hamilton (1963; 1964), in an attempt to produce an answer to Darwin’s unsolved puzzle of the existence of sterile castes in insects, demonstrated that such ‘altruism’ (i.e. sacrifice of one’s own reproductive fitness to further that of others) could spread in populations if certain conditions were met. Haldane had made the half-serious suggestion that while he would not lay down his life for his brother, he would for two brothers or eight first cousins. Hamilton (along with Maynard Smith 1964) worked out the mathematical genetics of this self-sacrificial behaviour in which it paid altruists, in terms of their own reproductive fitness, to sacrifice their immediate fitness (offspring) in so far as in doing so they preserved the fitness of enough relatives, who carried genes identical by descent with their own, to compensate. The logic of this implied that the real units of evolution were in fact the genes themselves, and that organisms were the mechanisms, or vehicles, by which the genes ensured that replicas of themselves were reproduced. This logic was beautifully worked out by Dawkins (1976) who coined the now popular term ‘selfish gene’.
The originality of Hamilton’s position, however, was to show how ‘altruism’ and ‘selfishness’ were two sides of the same coin, and not necessarily incompatible. In helping relatives we were, in genetic terms at least, helping ourselves. To this interesting mix Trivers (1971) added the necessary formula to deal with altruism towards strangers, again demonstrating how this could evolve if there were a pay-off for the altruist. Maynard Smith had shown how game theory could handle much of the conceptual and mathematical elements of this theory, and the philosopher’s favourite paradox of the ‘Prisoners’ Dilemma’ became the foundation of theories of what Trivers dubbed ‘reciprocal altruism’. A major element of this theory involved the possibility of cheating, since freeloaders could always take the benefits without paying the costs. They could not, however, do this to excess since there would then be no altruists to cheat. Hence arose the concept of the evolutionary stable strategy (ESS), in which two such behaviours could evolve in tandem.
Thus two powerful new concepts were developed: the concept of inclusive fitness, the fitness of the individual plus that of those with whom the individual shared genes in common by descent; and the concept of reciprocal altruism. A corollary of inclusive fitness was kin selection, which sounds like group selection in that it sees selection working essentially on units of related organisms. The difference essentially is that kin selection does not need to assume that behaviours evolve for these groups, but only for the benefit of individuals and their gene replicas in other organisms. Trivers (1972) further added the concept of parental investment (PI), which clarified the differing roles of the sexes in the rearing to viability of their offspring and hence the problems of parent-offspring and sibling-sibling conflict, as well as the profound asymmetry in male and female mating strategies. As a consequence attention was called to Darwin’s neglected concept of sexual selection especially as it affected differential male—female reproductive strategies
One might say that sociobiology in the narrower sense was born when E.O.Wilson (1975) took these theoretical concepts, married them to the data of entomology, ethology and primatology, and produced a ‘new synthesis’ to replace and advance the ‘modern synthesis’ of Huxley. Wilson’s ambition (which was anything but narrow) was to order all behaviour across species, from insects through primates to humans, according to the set of principles deriving from the precepts of Williams, Maynard Smith, Hamilton and Trivers. The influence of his massive synthesis has been profound, not only on the science of human behaviour, but also throughout the biological sciences. We, however, are concerned here with the subsequent developments in the study of human social behaviour.
Largely under the influence of Alexander (1974), a school of sociobiological thought emerged which took as its central precept the maximization of reproductive success. Its main assumption is that such maximization—deriving directly from Darwinian fitness—is a basic motive and can explain a whole range of human mating and kin-related behaviours. It married this idea to the basic ideas of kin altruism (‘nepotism’), inclusive fitness, parental investment and paternity certainty. Thus organisms—humans included—would strive to maximize reproductive success through inclusive fitness, and attempt to ensure (largely in the case of males) that the genes they ‘invested’ in were their own, that is, ensure the certainty of paternity. Ethnographic, sociological and historical examples were ransacked to discover examples of these principles at work. Thus the problem of the avunculate (the special relationship between mother’s brother and sister’s son) and hence the origins of matrilineal descent were attributed to ‘low paternity certainty’ in promiscuous societies where males would prefer to invest in sisters’ sons with a low but definite degree of genetic relationship, rather than their own sons whose degree of relationship could be zero (Alexander, Kurland, Hartung; for a critique see Fox 1993). The logic of this general position has been applied to hypergamy (Dickeman), despotic polygyny (Betzig), child abuse (Daly and Wilson), legal decisions (Beckstrom), kin support in illness (McGuire), family structure (van den Berghe), cross-cousin marriage (Alexander), mate competition, kin-term manipulation (Chagnon), polyandry (Crook), bridewealth (Irons, Mulder), morality (Alexander), parental care (Hames, Turke, Hill, Kaplan), among many others. (See, e.g. Betzig et al. 1988; Chagnon and Irons 1979; for a review of the state of the art, see King’s College Sociobiology Group 1982; issues of the journal Ethology and Sociobiology.)
Another tradition, however, rejects the primacy of reproductive fitness maximizing. It argues that while differential reproductive success in the past, and particularly in the species’ environment of evolutionary adaptation (EEA), certainly led to specific adaptations, no such generalized motive can explain ongoing behaviour. The motive, it is argued, does not give specific enough instructions to the organism, which is more likely to act on proximate motives like desire for sex, avoidance of cheaters, accrual of resources, achievement of status, etc. These may well lead to reproductive success, but they are not based on any general desire for its maximization. Studies, then, of contemporary behaviour which demonstrate—as do many of the studies cited above—that certain practices in certain circumstances lead to reproductive success, or that they involve nepotistic actions towards kin, tell us only that ongoing behaviour shows ingenious adaptability, but tell us nothing about whether or not these practices stem from genuine evolutionary adaptations (see Symons 1992).
The influence, among other things, of cognitive science, has led many sociobiologists then to reject the ‘adaptation agnostic’ stance of their other brethren and to look for specific adaptational mechanisms in human perception and cognition (‘information processing mechanisms’), whether or not these lead to current reproductive success. This school of evolutionary psychology has attempted to devise means of testing for ‘domain specific algorithms’ in the human mind, and is firmly opposed to ‘domain general mechanisms’ such as are proposed, for example, by many artificial intelligence theorists. It is sympathetic to those philosophers of mind like Fodor who prefer a modular to a unitary model of mind, and echoes, for example, Lumsden and Wilson’s idea of ‘epigenetic rules’ or the ‘biogrammar’ of Tiger and Fox, and various other developments in the field of ‘cognitive ethology’ and transformational grammar (‘the language acquisition device’). For example, Tooby and Cosmides have looked for cognitive mechanisms for social exchange and the detection of cheating, Buss for mate-preference mechanisms, Wilson and Daly for male proprietary behaviour, Silverman and Eals for sex differences in spatial ability, Profet for pregnancy sickness as an adaptive response to teratogens, and Orians and Heerwagen for evolved responses to landscape (see Barkow et al. 1992). Linguists, like Pinker, adhering to this approach, take issue with Chomsky and others who, while seeing linguistic competence as innate, do not see it as a product of natural selection. Evolutionary linguists see language, on the contrary, as having all the design hallmarks of an evolved adaptation. The ‘adaptationist’ school, however, like the one it rejects, is itself largely brain agnostic in that it does not try to link its domain specific modules to brain functions. But developments in neuroscience and artificial intelligence, particularly theories of parallel distributed processing (PDP), may well show the way to a future melding of these approaches (see Churchland 1993).
Sociobiology, both broadly and narrowly speaking, shows then a continuing vigorous development with influences in all the social sciences as well as philosophy and literature. Even criticisms of it have developed beyond simple-minded objections to genetic determinism or Social Darwinism to become serious attempts to grapple with the real issues (see Kitcher 1985). The general issue of conceptualizing the relation of genes and culture continues to be contentious (Boyd and Richerson 1985; Durham 1991), and the issue of group selection is by no means settled, but the future holds promise for the development of a normal science paradigm within which constructive disputes will be possible and cumulative progress made. The big question mark for the social sciences is the degree of their willingness to enter into a constructive debate with the sociobiologists now firmly established in their midst.
Robin Fox
Rutgers University
References
Alexander, R.D. (1974) ‘The evolution of social behavior’, Annual Review of Ecology and Systematic 5.
Barkow, J., Cosmides, L. and Tooby, J. (eds) (1992) The Adapted Mind: Evolutionary Psychology and the Generation of Culture, New York.
Betzig, L., Mulder, M.B. and Turke, P. (1988) Human Reproductive Behaviour: A Darwinian Perspective, Cambridge, UK.
Boyd, R. and Richerson, P.J. (1985) Culture and the Evolutionary Process, Chicago.
Chagnon, N. and Irons, W. (1979) Evolutionary Biology and Human Social Behavior, North Scituate, MA.
Churchland, P.S. (1993) Neurophilosophy: Toward a Unified Science of the Mind/Brain, Cambridge, MA.
Darwin, C. (1859) On the Origin of Species by Means of Natural Selection, London.
Dawkins, R. (1976) The Selfish Gene, Oxford.
Durham, W.H. (1991) Coevolution: Genes, Culture and Human Diversity, Stanford, CA.
Eibl-Eibesfeldt, I. (1975) Ethology: The Biology of Behavior, New York.
——(1989) Human Ethology, New York.
Fox, R. (1993) Reproduction and Succession, New Brunswick, NJ.
Fox, R. and Fleising, U. (1976) ‘Human ethology’, Annual Review of Anthropology, 5, Palo Alto, CA.
Hamilton, W.D. (1963) ‘The evolution of altruistic behavior’, American Naturalist 97.
——(1964) ‘The genetical evolution of social behavior’, Journal of Theoretical Biology 7.
Huxley, J. (1942) Evolution: The Modern Synthesis, London.
King’s College Sociobiology Group (eds) (1982) Current Problems in Sociobiology, Cambridge, UK.
Kitcher, P. (1985) Vaulting Ambition, Cambridge, MA.
Maynard Smith, J. (1964) ‘Group selection and kin selection’, Nature 289.
Mayr, E. (1982) The Growth of Biological Thought, Cambridge, MA.
Symons, D. (1992) ‘On the use and abuse of Darwinism in the study of human behavior’, in Barkow et al. (eds) The Adapted Mind, New York.
Tiger, L. and Fox, R. (1971) The Imperial Animal, New York.
Trivers, R.L. (1971) ‘The evolution of reciprocal altruism’, Quarterly Review of Biology 46.
——(1972) ‘Parental investment and sexual selection’, in B. Campbell (ed.) Sexual Selection and the Descent of Man 1871–1971, Chicago.
Williams, G.C. (1966) Adaptation and Natural Selection, Princeton, NJ.
Wilson, E.O. (1975) Sociobiology: The New Synthesis, Cambridge, MA.
Wynne-Edwards, V.C. (1962) Animal Dispersion in Relation to Social Behaviour, Edinburgh.
