Researchers from across the social sciences have found consistent deviations from the predictions of the canonical model of self-interest in hundreds of experiments from around the world. This research, however, cannot determine whether the uniformity results from universal patterns of human behavior or from the limited cultural variation available among the university students used in virtually all prior experimental work. To address this, we undertook a cross-cultural study of behavior in ultimatum, public goods, and dictator games in a range of (...) small-scale societies exhibiting a wide variety of economic and cultural conditions. We found, first, that the canonical model – based on self-interest – fails in all of the societies studied. Second, our data reveal substantially more behavioral variability across social groups than has been found in previous research. Third, group-level differences in economic organization and the structure of social interactions explain a substantial portion of the behavioral variation across societies: the higher the degree of market integration and the higher the payoffs to cooperation in everyday life, the greater the level of prosociality expressed in experimental games. Fourth, the available individual-level economic and demographic variables do not consistently explain game behavior, either within or across groups. Fifth, in many cases experimental play appears to reflect the common interactional patterns of everyday life. Key Words: altruism; cooperation; cross-cultural research; experimental economics; game theory; ultimatum game; public goods game; self-interest. (shrink)

We would like to thank the commentators for their generous comments, valuable insights and helpful suggestions. We begin this response by discussing the selfishness axiom and the importance of the preferences, beliefs, and constraints framework as a way of modeling some of the proximate influences on human behavior. Next, we broaden the discussion to ultimate-level (that is evolutionary) explanations, where we review and clarify gene-culture coevolutionary theory, and then tackle the possibility that evolutionary approaches that exclude culture might be sufficient (...) to explain the data. Finally, we consider various methodological and epistemological concerns expressed by our commentators. (shrink)

As a result of a spate of studies geared to investigating Brazilian racial categories, it is now believed by many that Brazilians reason about race in a manner quite different to that of Americans. This paper will argue that this conclusion is premature, as the studies in question have not, in fact, investigated Brazilian categories. What they have done is elicit sorting tasks on the basis of appearances, but the cognitive models of respondents have not been investigated in order to (...) determine what are the boundaries of their concepts. Sorting based on appearances is not sufficient to infer the boundaries of concepts whenever appearance is not a defining criterion for the concepts in question, as the case appears to be for racial and ethnic categories. Following a critique of the methods used, I review a terminological and theoretical confusion concerning the use of the terms 'emic' and 'etic' in anthropology that appears directly responsible for the failure so far to choose methods appropriate to parsing the conceptual domain of 'race' in Brazil. (shrink)

In this essay I will explore the important connection between conformism as an adaptive psychological strategy, and the emergence of the phenomenon of ethnicity. My argument will be that it makes sense that nature made us conformists. And once humans acquired this adaptive strategy, I will argue further, the development of ethnic organization was inevitable. Understanding the adaptive origins of conformism, as we shall see, is perhaps the most useful way to shed light on what ethnicity is—at least when examined (...) from the functional point of view, which is to say from the point of view of the adaptive problems that ethnicity solves. I shall begin with a few words about our final destination. (shrink)

I argue that (1) the accusation that psychological methods are too diverse conflates “reliability” with “validity”; (2) one must not choose methods by the results they produce – what matters is whether a method acceptably models the real-world situation one is trying to understand; (3) one must also distinguish methodological failings from differences that arise from the pursuit of different theoretical questions.