The authors demonstrate that unselfish behavior is in fact an important feature of both biological and human nature. Their book provides a panoramic view of altruism throughout the animal kingdom--from self-sacrificing parasites to the human capacity for selflessness--even as it explains the evolutionary sense of such behavior.

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. (shrink)

The evolutionary problem of the units of selection has elicited a good deal of conceptual work from philosophers. We review this work to determine where the issues now stand.

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. (shrink)

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. (shrink)

Altruism has both an evolutionary and a psychological meaning. As the term is used in evolutionary theory, a trait is deemed altruistic if it reduces the fitness of the actor and enhances the fitness of someone else. In its psychological sense, the thesis that we have altruistic ultimate motives asserts that we care about the welfare of others, not just as a means of enhancing our own well-being, but as an end in itself. In Unto Others (hereafter UO), we consider (...) both evolutionary altruism (Part I) and psychological altruism (Part II) from an evolutionary perspective. We propose a multilevel selection theory to explain how altruism can evolve from group selection, based on Darwin’s solution to the problem. Our presentation of multilevel selection theory expands the range of topics beyond altruism in other respects as well. In Part I1 of UO, we evaluate the arguments, both conceptual and empirical, that philosophers and psychologists have advanced in an attempt to choose between psychological egoism and motivational pluralism. We conclude that these arguments are inconclusive. (shrink)

Wilson outlines the basic principles of evolution with stories that entertain as much as they inform, and shows how, properly understood, these principles can illuminate the length and breadth of creation, from the origin of life to the nature of religion. Now everyone can move beyond the sterile debates about creationism and intelligent design to share Darwin's panoramic view of animal and human life, seamlessly connected to each other. Evolution, as Wilson explains, is not just about dinosaurs and human origins, (...) but about why all species behave as they do--from beetles that devour their own young, to bees that function as a collective brain, to dogs that are smarter in some respects than our closest ape relatives. And basic evolutionary principles are also the foundation for humanity's capacity for symbolic thought, culture, and morality.--From publisher description. (shrink)

_A powerful treatise that demonstrates the existence of altruism in nature, with surprising implications for human society_ Does altruism exist? Or is human nature entirely selfish? In this eloquent and accessible book, famed biologist David Sloan Wilson provides new answers to this age-old question based on the latest developments in evolutionary science. From an evolutionary viewpoint, Wilson argues, altruism is inextricably linked to the functional organization of groups. “Groups that work” undeniably exist in nature and human society, although special conditions (...) are required for their evolution. Humans are one of the most groupish species on earth, in some ways comparable to social insect colonies and multi-cellular organisms. The case that altruism evolves in all social species is surprisingly simple to make. Yet the implications for human society are far from obvious. Some of the most venerable criteria for defining altruism aren’t worth caring much about, any more than we care much whether we are paid by cash or check. Altruism defined in terms of thoughts and feelings is notably absent from religion, even though altruism defined in terms of action is notably present. The economic case for selfishness can be decisively rejected. The quality of everyday life depends critically on people who overtly care about the welfare of others. Yet, like any other adaptation, altruism can have pathological manifestations. Wilson concludes by showing how a social theory that goes beyond altruism by focusing on group function can help to improve the human condition. (shrink)

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. (shrink)

The hypothesis of group selection fell victim to a seemingly devastating critique in 1960s evolutionary biology. In Unto Others (1998), 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. (shrink)

_A powerful treatise that demonstrates the existence of altruism in nature, with surprising implications for human society_ Does altruism exist? Or is human nature entirely selfish? In this eloquent and accessible book, famed biologist David Sloan Wilson provides new answers to this age-old question based on the latest developments in evolutionary science. From an evolutionary viewpoint, Wilson argues, altruism is inextricably linked to the functional organization of groups. “Groups that work” undeniably exist in nature and human society, although special conditions (...) are required for their evolution. Humans are one of the most groupish species on earth, in some ways comparable to social insect colonies and multi-cellular organisms. The case that altruism evolves in all social species is surprisingly simple to make. Yet the implications for human society are far from obvious. Some of the most venerable criteria for defining altruism aren’t worth caring much about, any more than we care much whether we are paid by cash or check. Altruism defined in terms of thoughts and feelings is notably absent from religion, even though altruism defined in terms of action is notably present. The economic case for selfishness can be decisively rejected. The quality of everyday life depends critically on people who overtly care about the welfare of others. Yet, like any other adaptation, altruism can have pathological manifestations. Wilson concludes by showing how a social theory that goes beyond altruism by focusing on group function can help to improve the human condition. (shrink)

Pathological Altruism presents a number of new, thought-provoking theses that explore a range of hurtful effects of altruism and empathy.

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.

The primary outcome of natural selection is adaptation to an environment. The primary concern of epistemology is the acquistion of knowledge. Evolutionary epistemology must therefore draw a fundamental connection between adaptation and knowledge. Existing frameworks in evolutionary epistemology do this in two ways; (a) by treating adaptation as a form of knowledge, and (b) by treating the ability to acquire knowledge as a biologically evolved adaptation. I criticize both frameworks for failing to appreciate that mental representations can motivate behaviors that (...) are adaptive in the real world without themselves directly corresponding to the real world. I suggest a third framework in which mental representations are to reality as species are to ecosystems. This is a many-to-one relationship that predicts a diversity of adaptive representations in the minds of interacting people. As “species of thought”, mental representations share a number of properties with biological species, including isolating mechanisms that prevent them from blending with other representations. Species of thought also are amenable to the empirical methods that evolutionists use to study adaptation in biological species. Empirical studies of mental representations in everyday life might even be necessary for science to succeed as a normative “truth-seeking” discipline. (shrink)

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.

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. (shrink)

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. (shrink)

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. (shrink)

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. (shrink)

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. (shrink)

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. (shrink)

We address the following issues raised by the commentators of our target article and book: (1) the problem of multiple perspectives; (2) how to define group selection; (3) distinguishing between the concepts of altruism and organism; (4) genetic versus cultural group selection; (5) the dark side of group selection; (6) the relationship between psychological and evolutionary altruism; (7) the question of whether the psychological questions can be answered; (8) psychological experiments. We thank the contributors for their commentaries, which provide a (...) diverse agenda for future study of evolution and morality. Our response will follow the organization of our book, distinguishing between evolutionary issues that concern fitness effects and psychological issues that concern motives. (shrink)

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. (shrink)

Evolutionary science (ES) and contextual behavioral science (CBS) have developed largely independently during the last half century. However, the earlier histories of these two bodies of knowledge are thoroughly entwined. ES provides a unifying theoretical framework for the biological sciences, and is increasingly being applied to human-related sciences. Meanwhile, CBS is concerned with influencing human behavior in a practical sense. This groundbreaking volume seeks to integrate ES and CBS to promote real, positive change in peoples' lives. Evolution and Contextual Behavioral (...) Science offers a unique glimpse into the histories of ES and CBS, shows how they are intrinsically linked, and outlines why their integration--or, reunification--is essential. By examining these two schools of thought side by side, you'll gain an understanding of why functional and contextual approaches in CBS need to be combined with ES for both fields to advance more rapidly. Finally, rather than the sequential relationship that is typically imagined between ES and CBS, you'll discover how an integrated relationship between these two sciences will result in a better framework for understanding predicting, and influencing human behavior--back cover. (shrink)

If sociopathy is a biological adaptation, it probably evolved in small social groups in which individuals lacked the social mobility required for a con-man strategy to work. On the other hand, conflicts between groups may have provided a large niche for sociopathy throughout human history.

We reinforce Thompson's points by providing a second example of the paradox that makes group selection appear counterintuitive and by discussing the wider implications of multilevel selection theory.

We thank Karen Canfell, Hamish Spencer and Ben Oldroyd for their commentaries. Below are some comments on the points they raise: 1. Is the Group Selection Debate Merely a Matter of Semantics? 2. Multi-Level Selection Theory versus Genic Selectionism 3. Heritability and Group Selection in Human Beings 4. Adaptationism.

Rachlin's substantive points about the relationship between altruism and self-control are obscured by simplistic and outdated portrayals of evolutionary psychology in relation to learning theory.

It is a foundational prediction of evolutionary theory that human beliefs accurately approximate reality only insofar as accurate beliefs enhance fitness. Otherwise, adaptive misbeliefs will prevail. Unlike McKay & Dennett (M&D), we think that adaptive belief systems rely heavily upon misbeliefs. However, the case for positive illusions as an example of adaptive misbelief is weak.

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. (shrink)

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?

Rolls's mechanistic account of emotion can help to bridge a rift within the field of evolutionary psychology. One side of the rift emphasizes the importance of innate psychological mechanisms that evolved to solve specific problems encountered in the ancestral environment. The other side emphasizes learning, development, and culture as open-ended evolutionary processes in their own right. Rolls shows how these two views can be reconciled, allowing a productive middle ground to be explored.