Abstract

This book is a manifesto for what John Alcock calls “orthodox sociobiology,” the systematic study of the biological basis of all social behavior following the premise that behaviors and their mechanisms evolve under the primary influence of natural selection acting on individual differences in genetic success. Sociobiology focuses narrowly on finding adaptive explanations for social behaviors while attempting a grand synthesis of biological and social sciences. Alcock's book is largely defensive, aimed at refuting criticisms and a perception that, twenty‐five years after its proclamation, sociobiology is moribund. Alcock's defense relies not on an extensive review of relevant literature but on the persuasiveness of arguments illustrated with favored examples. He emphasizes sociobiology of human cultures and prescribes practical applications for restructuring societal institutions.The major argument against orthodox sociobiology is summarized in Edward O. Wilson's book Consilience : “We know that virtually all of human behavior is transmitted by culture. We also know that biology has an important effect on the origin of culture and its transmission. … Culture allows a rapid adjustment to changes in the environment through finely tuned adaptations invented and transmitted without correspondingly precise genetic prescription. In this respect human beings differ fundamentally from all other animal species” . This argument denies that human social behaviors are best understood as biologically evolved adaptations and places them outside the domain of the genetical theory of natural selection.Alcock's major claim for sociobiology's triumph is its use of comparative methodology to identify ultimate causes of social behaviors. Over the past twenty‐five years, evolutionary biologists have developed rigorous systematic methodologies for making comparative inferences in evolutionary research. Such explicitly phylogenetic approaches provide more powerful tests of ultimate causality in evolution than the comparative methods available when sociobiology was first proposed. Although the success of sociobiology would seem to lie in its ability to use the strongest comparative methods to test its major claims, Alcock's examples rely entirely on archaic methodology that no contemporary evolutionist should accept.The hypothesis of adaptation predicts that a character enhances its possessor's ability to utilize resources for survival or reproduction relative to alternatives against which it has been tested evolutionarily. Phylogenetic analysis of species possessing the character and their closest relatives identifies the comparisons appropriate for testing this hypothesis. Hypothetical adaptations are mapped onto phylogenies to identify their origins, antecedent conditions, associated characters, environmental contexts, and selective regimes. Alcock forfeits the power of evolutionary study by arguing that sociobiologists “can only use data from unrelated species known to experience similar selection pressures” in the “independent convergence test” of adaptation. No animal species are completely unrelated, nor are their behaviors adaptive in an absolute sense. Even comparisons of analogous characters across species must consider phylogeny because homologous genes and developmental programs can be utilized for analogous roles in different species. Without a firm grounding in phylogenetic principles, Alcock's methods cannot effectively test hypotheses of evolutionary causality.Alcock spends much effort defending sociobiology against the criticism that its major claims constitute untestable adaptationist stories. David Barash's sociobiological interpretations of mating behavior in bluebirds receive particular attention because Stephen Jay Gould criticized them as untestable. Alcock shows that Barash and others have empirically rejected some explanations in favor of better ones, although the hypotheses tested and the knowledge gained reside entirely in proximate mechanisms, not the ultimate causes that constitute sociobiology's main challenge. Gould's criticism therefore withstands Alcock's counterarguments.Readers unfamiliar with evolution should consult recent books such as Brian Hall's Evolutionary Developmental Biology , Jeffrey Levinton's Genetics, Paleontology, and Macroevolution , and John Avise's Phylogeography to see evolutionary disciplines that have triumphed over the past twenty‐five years. These disciplines contrast with sociobiology in their methodological rigor and profound reformulation of major theories. By contrast, Alcock's sociobiology seems essentially unchanged from the 1970s. If twenty‐five years of sociobiological study have produced only a repetition of its initial conjectures, their effectiveness as testable hypotheses seems doubtful.Alcock acknowledges “human evolutionary psychology” as a new subdiscipline of sociobiology. Indeed, orthodox sociobiology seems to be relocating from biology to psychology departments. My interpretation of this move is that sociobiology has not kept pace with evolutionary biology and therefore has sought refuge in a traditionally nonevolutionary discipline that has not yet incorporated the current critical standards of comparative evolutionary research.Sociobiology has served evolutionary biology mainly by revealing the limits of reductionist selective arguments, thereby directing us to move beyond them