Michael Ruse SOCIOBIOLOGY and REDUCTIONISM It Is Frequently
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Michael Ruse SOCIOBIOLOGY AND REDUCTIONISM It is frequently said that sociobiology is reductionistic or. more precisely. since much that is said about sociobiology is critical. it is frequently said that sociobiology is unduly reductionistic (Lewontin. 1977; Lewontin et al. J 984). In this discussion, I want to explore the precise meaning of such a charge as this, and whether or not it is justified. I hasten to add, at once, that I am not concerned here with either defending or attacking sociobiology per se. I and others have had much to say about this topic elsewhere -- some would say: "Too much to say about this topic elsewhere." Rather, I want to do what perhaps should have been done long ago.! want to provide a conceptual analysis of the way or ways in which one might speak of sociobiology in the context of reductionism. I shall begin by characterizing sociobiology very briefly. Then I shall move on to an even briefer discussion of the various senses in which the term "reductionism" is commonly used. After that, it will be possible to put the two concepts together and to see what results. SOCIOBIOLOGY Sociobiology is the study of organisms. most particularly animals. in their social relationships, from an evolutionary perspective (Wilson, 1975; Ruse. 1979). Although the name is new, as a subject it goes back to the founding classic of evolutionary theory, Charles Darwin's On the Origin of Species (1859). In that work. Darwin argued that all organisms. living and dead. are the product of a slow. gradual law-bound process of evolution. fuelled by a mechanism which he labelled "natural selection". Darwin argued that many more organisms are born than can possibly survive and reproduce. and that those which are successful in life's struggle the "fitter" -- are. as it were. naturally picked out from the breeding pool. for future generations. Given enough time. this natural selecting of 45 P. Hoyningen-HueM and F. M. Wuketits (eds.), Reductionism and Systems Theory in the Life Sciences. 45-83. @ 1989 by Kluwer Academic Publishers. 46 MICHAEL RUSE the successful leads to full-blown evolutionary change. What was crucial to Darwin, and continues to be so for his followers, is that selection does not simply lead to alteration, but promotes adaptation or proper functioning. Organisms work. They have features and characteristics which aid their attempts to succeed in the struggle for existence. They have eyes, fins, teeth, hair, feathers, leaves, roots, branches -- all of these things are adaptations, helping their possessors in life's struggles (Ruse, 1979b). In the Origin, Darwin was quite explicit in his intention to apply his theory to behaviour. What an organism does Is just as much part of Its nature as its anatomy. But, Darwin wanted to go beyond mere behavior to social interactions, particularly between animals of the same species. Darwin argued that, although life is a struggle, this does not necessarily always imply hand-to-hand all-out conflict. -- "Nature red in tooth and claw", as the poet Tennyson had expressed it. Darwin argued that cooperation between organisms can, under certain circumstances. be just as much a product of evolutionary process as can any other characterist.ic. Furthermore, Darwin backed up this belief by discussing in some length the paradigmatic example of sociality in the organic world, namely the so-called SOCial insects (part.icularly the hymenoptera, the wasps, ants and bees). Darwin claimed that the nature of the sterile workers in the hymenoptera must be just as much a consequence of the selective process, as any other feature that we may encounter. In the one hundred or more years since the Origin, evolutionary studies, particularly neo-Darwinian studies, have exploded outwards and upwards with great success. However, for a number of reasons, until recently the study of social behavior by evolutionists lagged far behind. The chief reason. of course, was the most obvious, namely that behavior is very, very much more difficult to study than other aspects of organisms. It is much easier to tell something about the eye colour of a fruit fly than about its mating habits. Thus, nat.urally. evolutionists tended to concentrate on more readily discernible aspects of organisms, leaving behavior (including social behavior) until later. Backing up this reason for the neglect of behavior were strong Ideological waves coming from the newly-growing social sciences. For fairly straight-forward reasons, workers in such fields as psychology and sociology felt very tense about the idea that biology might have anything to contribute to their areas of inquiry. And so there grew up a strong bias in favour of non-biological approaches to the understanding of social behavior (even including, indeed especially Including, studies of the social behavior of non-human animals). There were, nevertheless, some who looked at aspects of behavior from an evolutionary perspective. Most notably, in the years before and after the last War, the so-called "ethologists" looked at various questions to do with the interaction SOCIOBIOLOGY AN REDUCTIONISM 47 between or~anisms. particularly social interactions between organisms of the same species (Lorenz. 1952: Tinbergen. 1953a. b). However. t.his W:lS but a harbinger of what was to come, for some two decades ago (at the beginning of the 1960's) the whole study of the evolution of social behavior suddenly broke wide open. New ideas were introduced. new experimental results were gathered. new long-term naturalistic observations of animals in the wild were launched. From being the ugly duckling of the evolutionary family. the study of social behavior suddenly became a very proud and magnificent young swan indeed. In fact. it even gathered into itself a whole new name, namely "sociobiology". (A good Introduction is Barash. 1982.) INDIVIDUAL SELEC'rION Sociobiologists are orthodox Darwinians. That is to say. in today's context, they believe that the major evolutionary motive force is natural selection. and that this works ultimately on the units of heredity. These units -- the "genes" -- are carried by org:lnisms, within populations, and are transmitted through reproduction from one generation to another. All new variation within populations. on which natural selection must work ultlm:ltely, comes about through random changes ("mutations") caused at the level of the genes. There is. therefore, no overall direction or purpose to evolutionary change. What works, succeeds (WllJlams, 1966). What distinguishes sociobiologists most strongly from their ethological and other predecessors (although, incidentally, not from Charles Darwin himself) is the extent to which they take an IndivIdualistic stance towards natural selection (Ruse, 1979a, 1980; Brandon and Burian, 1984). What does this mean? Consider for a moment the way in which natural selection might be presumed to act, and ask yourself the favourite question of lawyers, namely cui bono (who gains)? When a new adaptation is produced by selection, for whose benefit does the adaptation exist :lnd function? Is the end worth of an adaptation directed towards the actual individual possessor of that adaptation, that is to say, the Individual organism; or is the end worth of the adaptation directed towards the good of the organism's group, where "group", in most contexts, would be interpreted as the organism's interbreeding group (I.e., the organism's species)? With some reservations and clarifications to be noted later, sociobiology's most distinctive characterizing feature is the extent to which It opts firmly for the Individualistic solution (Dawkins, 1976). It is the claim of today's Darwinian students of social behavior that such behavior is caused by natural selectIon working at the level of the Individual and not at the level of the group. Mutual 48 MICHAEL RUSE aid. cooperation or. as sociobiologists like to call it. "altruism". must be understood as something which benefits the individual actors. It does not exist for the overall good of the species. In taking such a stand as this. sociobiologists separate themselves firmly from ethologists. like the Nobel Prize winner KonTad Lorenz. In his well-known book. On Aggnsslon (1966). Lorenz argued that the reason why animals never fight to kill is that such all-out combat would be harmful to the species. Sociobiologists challenge this interpretation. absolutely. They argue that any restrained aggression or like behavior must be understood in terms of individual benefits alone. In the particular case of restrained aggression. it is argued that although it might benefit the winner to kill the loser. all too often we ourselves are losers. Therefore. it is in our own interests that aggression be restrained (Maynard Smith. 1972. 1974). Given that they take so individualistic a stance about selection. sociobiologists have found it necessaTY to devise various special models or mechanisms to account for particular facets of social behavior. It is here that they feel that they have scored their gTeatest triumphs. Amongst the various models which have been proposed we might. by way of illustration. mention the two which are most widely used. First. there is "kin selection". Here It Is pointed out that the key to reproductive success lies In passing on one's own units of heredity. that Is to say. in maintaining and perhaps increasing the proportion of one's own genes in future generations. However. obviously. one does not pass on one's own genes literally, but rather copies of such genes. But. remember that relatives will share genes. (By fairly elementary considerations one can show. for instance. that siblings are 50 % related. with corresponding diminution as the circle of relatedness widens.) What this all means. therefore, Is that inasmuch as one's relatives reproduce. one is oneself reproducing vicariously! If. for instance. my sister has children then. indirectly. she is poring my genes (or rather.