Richard D. Alexander

Aggressiveness, Territoriality, and Sexual Behavior in Field Crickets (Orthoptera: Gryllidae)

Most contacts between adult male field crickets involve aggressive behavior by one or both individuals and terminate with the obvious retreat of one individual. Aggressive behavior consists of one or more of several actions: in mild encounters there is either rearing of the forebody, lashing of the antennae, and shaking of the body, or else rearing of the hind body, kicking with the hind legs, and shaking of the body; in intense encounters, antennal lashing and rearing of the forebody are followed by spreading the mandibles, stridulating distinctively, rushing forward, sparring with the forelegs, butting with the head, and grappling, wrestling, or biting with the mandibles. A male is often flipped back or thrown sideways, but mutilation as a result of fighting is rare, and only in the most intense encounters is the winner determined by what seems to be superior strength or fighting ability. The outcomes of most encounters are determined by the relative tenacity of the two males, and the intensity of aggression exhibited is correlated with the length of the fight, continued aggressive activity developing into increasingly severe combat until one male finally retreats. Groups of adult male field crickets caged in small arenas form essentially linear dominance hierarchies which are stable for short periods of time and which can be described in terms of several characteristics: (1) each male dominates all or nearly all of his encounters with males below him in the hierarchy, (2) the total number of encounters by individual males decreases gradually toward the bottom of the hierarchy, (3) the intensity of aggression exhibited during encounters decreases more or less gradually toward the bottom of the hierarchy and the numbers of no-decision and no-aggression encounters and actively homosexual contacts increase, and (4) encounters between males which rank next to each other are usually more intense than encounters between males which are far apart in the hierarchy.

Culture Theory: The Developing Synthesis from Biology

ConclusionsWe believe that a useful, complete theory of culture is simpler than the dichotomies promoted by the coevolutionary approach suggest. Culture can be regarded as an aspect of the environment into which each human is born and must succeed or fail, developed gradually by the succession of humans who have lived throughout history. We hypothesize that culture results from the inclusive-fitness-maximizing efforts of all humans who have lived. We think the evidence suggests that cultural traits are, in general, vehicles of genic survival, and that the heritability of cultural traits depends on the judgments (conscious and unconscious) of individuals with regard to their effects on the individuals inclusive fitness.The challenge now before students of culture is to understand the proximate mechanisms, especially the ontogeny of learning biases, that result in the acquisition and transmission of cultural traits. How, for example, do we learn what constitutes an appropriate return on a social investment in different circumstances; i.e., what causes us to feel rewarded by, say, helping offspring who do not help us back, yet consistently to begrudge lesser expenditures to most others, or to feel cheated if we are not compensated for such expenditures immediately? We suggest that the answers to such questions lie in a few basic evolved learning tendencies.

Human hips, breasts and buttocks: Is fat deceptive?

Abstract In humans, reproductive-age females, unlike other ages and classes of individuals, deposit fat preferentially on the breasts, hips, and buttocks. This suggests that such fat deposition is a deceptive sexual signal, mimicking other signals of high reproductive value and potential.

Biology and Law

Abstract The terms “biology” and “biological” are widely used in ways that confuse and denigrate possible contributions of biologists to human self-understanding. As with social scientists, biologists deal with learning, developmental plasticity, and strategizing in virtually all species they study. It is from theories about how human strategizing is molded by selection that biologists can contribute to understanding topics like law.

Social learning and kin recognition: An addendum and reply to Sherman

A s Sherman (this issue) notes, I tried (Alexander 1990) to determine “the extent to which social learning, especially without self-reference, can account for the kin recognition findings of different investigators with different organisms . . . (p. 273). I had two motivations. First, I have had difftculty modeling the evolution of kin recognition via mechanisms that can function in the absence of social learning (Alexander and Borgia 1978; Alexander 1979, 1990). Second, it seemed to me that virtually all investigators of kin recognition were searching for unusual or cryptic mechanisms like use of self (without additional referents. Alexander 1979, 1990) or so-called “recognition alleles” or “genetic models,” and partly for that reason were in danger of biasing themselves away from thorough searches for opportunities for social learning. I think I provided evidence that the second argument is sometimes appropriate, by showing that several results previously regarded as unexplainable except as a result of self-referencing may indeed be outcomes of social learning opportunities that had been overlooked. Examples are Holmes’ (1986b) results with paternal half siblings in ground squirrels and Sherman and Holmes’ (1985) results with full and (maternal) half sister discrimination in ground squirrels. In Holmes’ experiment, juvenile ground squirrels were in fact exposed to the traits of fathers they shared with unfamiliar (nonlittermate) paternal half siblings through littermates that also shared that father. For the more complicated case of full and (maternal) half sisters in ground squirrels, I provided non-intuitive predictions (Alexander 1990, p. 277) that can be used to test my hypothesis based on imperfect social learning. I also tried to explain two effects that might be mistaken for either selfreferencing or “recognition alleles.” The first is that imperfections in social learning can give the impression of unusual mechanisms by causing organisms to behave as though they recognize relatives with which they have not associated when in fact they are simply mistaking them for associates. I

Biology and the moral paradoxes

Considerations from biology suggest (1) that human interests can be generalized as reproductive, involving activities by individuals that tend to promote the survival of their individualized sets of genes; (2) that ethical, moral and legal questions arise out of conflicts of interest that exist because of our history of genetic differences; (3) that human behavior probably always involves egoistic tendencies and moral inconsistency; (4) that the stages of moral development described by social scientists correspond to the patterns of life effort discussed by biologists; (5) that the idealized moral systems of philosophy and religion have been developed as models that are promoted in others but not (or more than) in ones self; and (6) that what are usually seen as the closest approaches to these idealized models are the sources of our most severe problems because they involve between-group competition and strife.

Natural Selection and Societal Laws

Ever since Darwin published his Origin of Species literate people have tended to regard the attributes of living things as outcomes of an evolutionary process, and to suppose that humans like other organisms are in some way derived through organic evolution. In terms of searches for explanation there are several meanings to this remark. Laboratory scientists, for example, may assume that common or similarly derived mechanisms underlie physiological phenomena observed even in widely different animals, and they may as a result use simpler or more easily studied organisms, such as rats, to help understand complex species, such as humans, which are difficult to study in the laboratory. Primatologists may assume that humans are similar to other primates because of genetic similarity or a recent common ancestry; this assumption may be used in developing and testing theories about human behavior and its history, or about the phylogenetic derivation of humans. Paleontologists assume that the phylogenetic patterns they are able to trace across geological time are the result of mutation, selection, and isolation, as observable today, even though they are hardly ever able to reconstruct the environments in which the changes occurred well enough to understand the adaptive significance of ancient trends.

Communicative Mandible-Snapping in Acrididae (Orthoptera)

Paratylotropidia brunneri Scudder is the first insect known to possess a long-range mandibular sound signal. This signal probably evolved through a stage in which feeding noises were significant; it is believed to be a functional analog of other insect calling sounds.

Genes, consciousness, and behavior theory.

During the past two decades, a theoretical revolution has occurred in evolutionary biology. It is a revolution that concerns the generation-to-generation operation of microevolution, and therefore the interpretation of long-term cumulative changes in macroevolution. It has focused our attention on what I believe to be the most profound paradox of human existence, and on phenomena important to everyone concerned with understanding the complexity of human behavior and of the human psyche. I will approach this topic by considering, first, some of my own personal reflections on disagreements between biologists and psychologists which have fascinated and bothered me since I took my last formal course as a doctoral student over twenty-five years ago. That was a seminar in physiological and comparative psychology taught by Donald R. Meyer at The Ohio State University. I happened to take it shortly after the appearance of Lehrmans (1953) critique of Lorenz (1950), and in a year when the mission of the seminar was to tear to shreds the arguments advanced by Niko Tinbergen (1951) in his then fairly new book The Study of

Evolution, Social Behavior, and Ethics

Nothing seems likely to influence analyses of the relationship between science and ethics as much as would a significant revision of our view of either science or ethics. Yet refinements of evolutionary theory within biology during the past twenty years seem to me to have provided a compelling new model of culture and human sociality which dramatically alters our interpretations of all human activities, including both science and ethics. This model has been developed elsewhere and the findings responsible for it described;1 here I shall only summarize the attributes of the model, and the way in which it departs from earlier views, before discussing its apparent meaning for the current confrontation, or interaction, between science and ethics.