David Wilson

The naturalistic fallacy is mentionedfrequently by evolutionary psychologists as anerroneous way of thinking about the ethicalimplications of evolved behaviors. However,evolutionary psychologists are themselvesconfused about the naturalistic fallacy and useit inappropriately to forestall legitimateethical discussion. We briefly review what thenaturalistic fallacy is and why it is misusedby evolutionary psychologists. Then we attemptto show how the ethical implications of evolvedbehaviors can be discussed constructivelywithout impeding evolutionary psychologicalresearch. A key is to show how ethicalbehaviors, in addition to unethical behaviors,can evolve by natural selection.

I examine the relationship between evolutionary definitions of altruism that are based on fitness effects and psychological definitions that are based on the motives of the actor. I show that evolutionary altruism can be motivated by proximate mechanisms that are psychologically either altruistic or selfish. I also show that evolutionary definitions do rely upon motives as a metaphor in which the outcome of natural selection is compared to the decisions of a psychologically selfish (or altruistic) individual. Ignoring the precise nature of both psychological and evolutionary definitions has obscured many important issues, including the biological roots of psychological altruism.

  The naturalistic fallacy is mentionedfrequently by evolutionary psychologists as anerroneous way of thinking about the ethicalimplications of evolved behaviors. However,evolutionary psychologists are themselvesconfused about the naturalistic fallacy and useit inappropriately to forestall legitimateethical discussion. We briefly review what thenaturalistic fallacy is and why it is misusedby evolutionary psychologists. Then we attemptto show how the ethical implications of evolvedbehaviors can be discussed constructivelywithout impeding evolutionary psychologicalresearch. A key is to show how ethicalbehaviors, in addition to unethical behaviors,can evolve by natural selection

Many evolutionary models assume that behaviors are caused directly by genes. An implication is that behavioral uniformity should be found only in groups that are genetically uniform. Yet, the members of human social groups often behave in a uniform fashion, despite the fact that they are genetically diverse. Behavioral uniformity can occur through a variety of psychological mechanisms and social processes, such as imitation, consensus decision making, or the imposition of social norms. We present a series of models in which genes code for social transmission rules, which in turn govern the behaviors that are adopted. Transmission rules can evolve in randomly formed groups that concentrate phenotypic variation at the between-group level, favoring the evolution of altruistic behaviors and other group-advantageous traits. In addition, a direct bias toward adopting altruistic behaviors can evolve. Our models begin to show how group selection can be a strong force in human evolution, despite the absence of extreme genetic variation among groups

Words such as selfish and altruistic that describe conduct toward self and others are notoriously ambiguous in everyday language. I argue that the ambiguity is caused, in part, by the coexistence of multiple belief systems that use the same words in different ways. Each belief system is a relatively coherent linguistic entity that provides a guide for human behavior. It is therefore a functional entity with design features that dictate specific word meaning. Since different belief systems guide human behavior in different directions, specific word meanings cannot be maintained across belief systems. Other sources of linguistic ambiguity include i) functional ambiguity that increases the effectiveness of a belief system, ii) ambiguity between belief systems that are functionally identical but historically distinct, and iii) active interference between belief systems. I illustrate these points with a natural history study of the word selfish and related words in everyday language. In general, language and the thought that it represents should be studied in the same way that ecologists study multi-species communities.

Humans possess great capacity for behavioral and cultural change, but our ability to manage change is still limited. This article has two major objectives: first, to sketch a basic science of intentional change centered on evolution; second, to provide examples of intentional behavioral and cultural change from the applied behavioral sciences, which are largely unknown to the basic sciences community.All species have evolved mechanisms of phenotypic plasticity that enable them to respond adaptively to their environments. Some mechanisms of phenotypic plasticity count as evolutionary processes in their own right. The human capacity for symbolic thought provides an inheritance system having the same kind of combinatorial diversity as does genetic recombination and antibody formation. Taking these propositions seriously allows an integration of major traditions within the basic behavioral sciences, such as behaviorism, social constructivism, social psychology, cognitive psychology, and evolutionary psychology, which are often isolated and even conceptualized as opposed to one another.The applied behavioral sciences include well-validated examples of successfully managing behavioral and cultural change at scales ranging from individuals to small groups to large populations. However, these examples are largely unknown beyond their disciplinary boundaries, for lack of a unifying theoretical framework. Viewed from an evolutionary perspective, they are examples of managing evolved mechanisms of phenotypic plasticity, including open-ended processes of variation and selection.Once the many branches of the basic and applied behavioral sciences become conceptually unified, we are closer to a science of intentional change than one might think.

Norms have a strong influence on human social interactions, but the emotions and actions associated with norm-breaking events have not been systematically studied. We asked subjects to imagine themselves in a conflict situation and then to report how they would feel, how they would act, and how they would imagine the feelings and actions of their opponent. By altering the fictional scenario that they were asked to imagine (weak vs. strong norm) and the perspective of the subject (norm-breaker vs. the one whose norm has been violated), the emotions and actions associated with norm-breaking events could be examined. We tested the following hypotheses: (1) norms create emotional asymmetries that resolve conflicts in otherwise symmetrical contest situations; (2) sex differences exist in response to norm-breaking events, with males more prone to violence than females; (3) individual differences exist in response to norm-breaking events, along the lines predicted by theoretical models; and (4) emotions and actions attributed to one’s opponent are distorted in ways that can be interpreted as adaptive for the believer. In addition to these basic hypotheses, we address more subtle issues concerning the particular emotions provoked by norm-breaking events, the degree to which emotional response is fine-tuned to the situation, and the degree to which emotional response correlates with anticipated behavioral response. We discuss the relevance of our study to the general study of emotions and the use of fictional scenarios as a research method in addition to the study of norms from an evolutionary perspective

We thank the commentators for an extraordinarily diverse and constructive set of comments. Nearly all applaud our goal of sketching a unified science of change, even while raising substantive points that we look forward to addressing in our reply, which we group into the following categories: What counts as evolutionary; Ethical considerations; Complexity; Symbotypes, culture, and the future; What intentional cultural change might look like; An evolving science of cultural change; and Who decides?

Cooperation can evolve in the context of cognitive activities such as perception, attention, memory, and decision making, in addition to physical activities such as hunting, gathering, warfare, and childcare. The social insects are well known to cooperate on both physical and cognitive tasks, but the idea of cognitive cooperation in humans has not received widespread attention or systematic study. The traditional psychological literature often gives the impression that groups are dysfunctional cognitive units, while evolutionary psychologists have so far studied cognition primarily at the individual level. We present two experiments that demonstrate the superiority of thinking in groups, but only for tasks that are sufficiently challenging to exceed the capacity of individuals. One of the experiments is in a brain-storming format, where advantages of real groups over nominal groups have been notoriously difficult to demonstrate. Cognitive cooperation might often operate beneath conscious awareness and take place without the need for overt training, as evolutionary psychologists have stressed for individual-level cognitive adaptations. In general, cognitive cooperation should be a central subject in human evolutionary psychology, as it already is in the study of the social insects

It is common to portray conservative and liberal Protestant denominations as “strong” and “weak” on the basis of indices such as church attendance. Alternatively, they can be regarded as qualitatively different cultural systems that coexist in a multiple-niche environment. We integrate these two perspectives with a study of American teenagers based on both one-time survey information and the experience sampling method (ESM), which records individual experience on a moment-by-moment basis. Conservative Protestant youth were found to be more satisfied, family-oriented, and sociable than liberal Protestant youth, but also more dependent on their social environment, which is reflected in a deterioration of their mood when they are alone. Liberal Protestant youth appear to have internalized values that remain constant whether in the presence or absence of others. We relate these results to the social scientific literature on liberalism and conservatism and to evolutionary theory as a framework for explaining cultural systems as adaptations to multiple-niche environments

Gossip is a subject that has been studied by researchers from an array of disciplines with various foci and methods. We measured the content of language use by members of a competitive sports team across 18 months, integrating qualitative ethnographic methods with quantitative sampling and analysis. We hypothesized that the use of gossip will vary significantly depending on whether it is used for self-serving or group-serving purposes. Our results support a model of gossip derived from multilevel selection theory that expects gossip to serve group-beneficial rules when rewards are partitioned at the group level on a scale that permits mutual monitoring. We integrate our case study with earlier studies of gossip conducted by anthropologists, psychologists, and management researchers.

It is a challenge to explain how evolutionary altruism can evolve by the process of natural selection, since altruists in a group will be less fit than the selfish individuals in the same group who receive benefits but do not make donations of their own. Darwin proposed a theory of group selection to solve this puzzle. Very simply, even though altruists are less fit than selfish individuals within any single group, groups of altruists are more fit than groups of selfish individuals. If a population is subdivided into many groups that vary in their altruistic tendencies, altruism will be favored at the level of selection among groups even as it is being disfavored at the level of selection among individuals within groups. Darwin’s scenario became the basis for a theoretical framework called multilevel selection theory.

In both biology and the human sciences, social groups are sometimes treated as adaptive units whose organization cannot be reduced to individual interactions. This group-level view is opposed by a more individualistic one that treats social organization as a byproduct of self-interest. According to biologists, group-level adaptations can evolve only by a process of natural selection at the group level. Most biologists rejected group selection as an important evolutionary force during the 1960s and 1970s but a positive literature began to grow during the 1970s and is rapidly expanding today. We review this recent literature and its implications for human evolutionary biology. We show that the rejection of group selection was based on a misplaced emphasis on genes as "replicators" which is in fact irrelevant to the question of whether groups can be like individuals in their functional organization. The fundamental question is whether social groups and other higher-level entities can be "vehicles" of selection. When this elementary fact is recognized, group selection emerges as an important force in nature and what seem to be competing theories, such as kin selection and reciprocity, reappear as special cases of group selection. The result is a unified theory of natural selection that operates on a nested hierarchy of units. The vehicle-based theory makes it clear that group selection is an important force to consider in human evolution. Humans can facultatively span the full range from self-interested individuals to "organs" of group-level "organisms." Human behavior not only reflects the balance between levels of selection but it can also alter the balance through the construction of social structures that have the effect of reducing fitness differences within groups, concentrating natural selection (and functional organization) at the group level. These social structures and the cognitive abilities that produce them allow group selection to be important even among large groups of unrelated individuals.

Group selection is increasingly being viewed as an important force in human evolution. This paper examines the views of R.D. Alexander, one of the most influential thinkers about human behavior from an evolutionary perspective, on the subject of group selection. Alexander's general conception of evolution is based on the gene-centered approach of G.C. Williams, but he has also emphasized a potential role for group selection in the evolution of individual genomes and in human evolution. Alexander's views are internally inconsistent and underestimate the importance of group selection. Specific themes that Alexander has developed in his account of human evolution are important but are best understood within the framework of multilevel selection theory. From this perspective, Alexander's views on moral systems are not the radical departure from conventional views that he claims, but remain radical in another way more compatible with conventional views.

We have two main objections to Kerr and Godfrey-Smith's (2002) meticulous analysis. First, they misunderstand the position we took in Unto Others – we do not claim that individual-level statements about the evolution of altruism are always unexplanatory and always fail to capture causal relationships. Second, Kerr and Godfrey-Smith characterize the individual and the multi-level perspectives in terms of different sets of parameters. In particular, they do not allow the multi-level perspective to use the individual fitness parameters i and i. We don't see why the multi-level perspective prevents one from thinking in these terms. Kerr and Godfrey-Smith's argument that Uyenoyama and Feldman's (1980, 1992) definition of altruism belongs more to the individualist perspective than it does to the multi-level perspective is an artifact of their choice of parameters; the same point applies to their argument about the individualism inherent in the idea of Class I and Class II fitness structures.

The hypothesis of group selection fell victim to a seemingly devastating critique in 1960s evolutionary biology. In Unto Others, we argue to the contrary, that group selection is a conceptually coherent and empirically well documented cause of evolution. We suggest, in addition, that it has been especially important in human evolution. In the second part of Unto Others, we consider the issue of psychological egoism and altruism -- do human beings have ultimate motives concerning the well-being of others? We argue that previous psychological and philosophical work on this question has been inconclusive. We propose an evolutionary argument for the claim that human beings have altruistic ultimate motives.