J. SociaI Biol. Struct. 1981 4, 329-346 Ultimate vs. proximate explanation: Explanatory modes in sociobiology and the social sciences Joseph Loseo Center for Biopolitical Research Since the publication of E. O. Wilson's Sociobiology, the New Synthesis, there has been speculation concerning the utility of applying the ultimate explanatory perspective utilized by sociobiologists to the particular phenomena and problems treated by the social sciences. Some critics of such application find ultimate explanations of little use in the study of human social behavior which has tradition- ally been explained in proximate terms. Indeed, as sociobiologists themselves have noted, the explanatory domains of ultimate and proximate causation are quite different. It is argued here that ultimate level analyses do not produce complete and satisfactory accounts of human behavior. Nor do they straightforwardly or un- ambt~Uotlsly imply proximate cause in a manner of direct use to social scientists. In f~ct, one of the principal shortcomings of ultimate level analysis is that it does not provide a clear picture of the nature of organismic functioning upon which the social sciences can build proximate models of behavior. Nevertheless, ultimate accounts are useful in a heuristic sense, serving to generate hypotheses which can revitalize social science research and permitting assessment of the status of proximite level hypothesis in light of evolutionary consequences. The bridging of ultimate and proximate levels of analysis, if it is to come at all, awaits the forging of translating principles not currently in place. 1. Introduction: a question of explanatory fit Proponents of sociobiology have, since the appearance of Edward O. Wilson's landmark Sociobiology, the New Synthesis, argued, often persuasively, that the evolutionary approach embodied in their position is capable of offering new insights into the explanation of social phenomena too long obscured by a social science wedded to an inadequate environmentalist view of man (Alexander, 1979a; Wilson, 1978; Barash, 1977; Ellis, 1977; Durham, 1976). They ground their analysis of human social behavior in the evolutionary history of the species, arguing that behavior can be understood best in light of the adaptive function it serves for individuals displaying it. The term 'ultimate' is usually applied to formulations so grounded. Social science, on the other hand, has traditionally examined social phenomena on the basis of the more immediate springs of behavior including motivation. Explanations utilizing this approach have been termed 'proximate' by comparison to evolutionary models. Sociobiology's successful application in the social sciences hinges in part upon the ability 0140-1750/81/040329 + 18 $02.00/0 © 1981 Acadmic Press Inc. (London) Limited