Misunderstandings often develop when scientists from different backgrounds use the same words (e.g., “selection”) when they mean different things by them. Theorists must therefore choose and define their terms carefully. In addition, proponents of “new” theories need to demonstrate empirically that theirs are more powerful than the existing theories they wish to supplant. Wilson & Sober have not yet done this.

The six commentaries raise five issues about multi-level selection theory that we attempt to address: (1) replicators without vehicles, (2) group selection and movement between groups, (3) absolute versus relative fitness, (4) group-level psychological adaptions, and (5) multi-level selection as a predictive theory.

One view of language is that it emerged in a single step in Homo sapiens, and depended on a radical transformation of human thought, involving symbolic representations and computational rules for combining them. I argue instead that language should be viewed as a communication system for the sharing of thoughts, and that thought processes themselves evolved well before the capacity to share them. One property often considered unique to language is generativity—the capacity to generate a potentially infinite variety of sentences. (...) I suggest that generativity is derived from the understanding of space and the capacity to recall or construct spatiotemporal scenarios, and probably goes far back in the evolution of animals that move in spatial habitats. Another property essential to language is theory of mind, the ability to understand what others are thinking, which probably emerged from animal empathy and became more complex in hominin evolution. Language evolved for the sharing of experiences, whether remembered or constructed, perhaps initially through pantomime but gradually conventionalized into standardized forms, including speech. These developments probably took place gradually during the Pleistocene, rather than as a sudden event in the evolution of H. sapiens. (shrink)

The task of Philosophy in Science (PinS) is to use philosophical tools to help solve scientific problems. This article describes how I stumbled into this line of work and then addressed several topics in philosophy of biology—units of selection, cladistic parsimony, robustness and trade-offs in model building, adaptationism, and evidence for common ancestry—often in collaboration with scientists. I conclude by offering advice for would-be PinS practitioners.

The influence that philosophy of science has had on scientific practice is as controversial as it is undeniable, especially in the case of biology. The dynamic between philosophy and biology as disciplines has developed along two different lines that can be characterized as 'paternal', on the one hand, and more 'fraternal', on the other. The role Popperian principles of demarcation and falsifiability have played in both the systematics community as well as the ongoing evolution-creation debates illustrate these contrasting forms of (...) interdisciplinary engagement, underscoring the influence philosophy of science in shaping our contemporary understanding of biology in the North American context. However, a strict disciplinary distinction between philosophy and science may itself be a false dichotomy that risks hampering future development of the biological sciences. By actively engaging with philosophical considerations as an integral part of their scientific practice, nineteenth-century biologists offer an interesting counterpoint to current trends of overspecialization and provide a model of scientists who avoided extremes of antagonism with, or subservience to, philosophy. (shrink)

My aim in this paper is to demonstrate that a very simple learning rule based on imitation can help to sustain altruism as a culturally transmitted pattern or behaviour among agents playing a standard prisoner’s dilemma game. The point of this demonstration is not to prove that imitation is single-handedly responsible for existing levels of altruism (a thesis that is false), nor is the point to show that imitation is an important factor in explanations for the evolution of altruism (a (...) thesis already prominent in the existing literature). The point is to show that imitation contributes to the evolution of altruism in a particular way that is not always fairly represented by evolutionary game theory models. Specifically, the paper uses a simple model to illustrate that cultural transmission includes mechanisms that do not transmit phenotype vertically (i.e. from parent to related offspring) and that these mechanisms can promote altruism in the absence of any direct biological propensity favouring such behaviour. This is a noteworthy result because it shows that evolutionary models can be built to explicitly reflect the contribution of non-vertical transmission in our explanations for the evolution of altruism among humans and other social species. (shrink)

Kin selection, reciprocity and group selection are widely regarded as evolutionary mechanisms capable of sustaining altruism among humans andother cooperative species. Our research indicates, however, that these mechanisms are only particular examples of a broader set of evolutionary possibilities.In this paper we present the results of a series of simple replicator simulations, run on variations of the 2–player prisoner's dilemma, designed to illustrate the wide range of scenarios under which altruism proves to be robust under evolutionary pressures. The set of (...) mechanisms we explore is divided into four categories :correlation, group selection, imitation, and punishment. We argue that correlation is the core phenomenon at work in all four categories. (shrink)

The social, behavioral, and a good chunk of the biological sciences concern the nature of individual agency, where our paradigm for an individual is a human being. Theories of economic behavior, of mental function and dysfunction, and of ontogenetic development, for example, are theories of how such individuals act, and of what internal and external factors are determinative of that action. Such theories construe individuals in distinctive ways.

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)

The six commentaries raise five issues about multi-level selection theory that we attempt to address: (1) replicators without vehicles, (2) group selection and movement between groups, (3) absolute versus relative fitness, (4) group-level psychological adaptions, and (5) multi-level selection as a predictive theory.

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)

This is a joint review of Shirley Strum and Linda Fedigan's Primate Encounters: Models of Science, Gender, and Society (Chicago, 2000) and Sarah Blaffer Hrdy, Mother Nature: A History of Mothers, Infants, and Natural Selection (Pantheon, 1999).

David Sloan Wilson has recently revived the idea of a group mind as an application of group selectionist thinking to cognition. Central to my discussion of this idea is the distinction between the claim that groups have a psychology and what I call the social manifestation thesis-a thesis about the psychology of individuals. Contemporary work on this topic has confused these two theses. My discussion also points to research questions and issues that Wilson's work raises, as well as their connection (...) to externalist conceptions of the mind familiar since the work of Putnam and Burge. (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)

According to historical theories of biological function, a trait's function is determined by natural selection in the past. I argue that, in addition to historical functions, ahistorical functions ought to be recognized. I propose a theory of biological function which accommodates both. The function of a trait is the way it contributes to fitness and fitness can only be determined relative to a selective regime. Therefore, the function of a trait can only be specified relative to a selective regime. Apart (...) from its desirable pluralism, only this view of relational function can support the function/accident and function/malfunction distinctions commonly thought to be part of the concept of function. Furthermore, only relational function correctly characterizes the explanatory consequences of function attributions in evolutionary biology. (shrink)

The paper aims to clarify and scrutinize Searle"s somewhat puzzling statement that collective intentionality is a biologically primitive phenomenon. It is argued that the statement is not only meant to bring out that "collective intentionality" is not further analyzable in terms of individual intentionality. It also is meant to convey that we have a biologically evolved innate capacity for collective intentionality.The paper points out that Searle"s dedication to a strong notion of collective intentionality considerably delimits the scope of his endeavor. (...) Furthermore, evolutionary theory does not vindicate that an innate capacity for collective intentionality is a necessary precondition for cooperative behavior. 1. (shrink)

Teilhard de Chardin developed an evolutionary vision of our planetary future, currently developing from a sphere of life, or biosphere towards a sphere of mind, or noosphere. As a visionary, Teilhard was not only on the brink of formulating the internet, but he also anticipated current academic efforts to understand globalization, as well as human, cultural and technological evolution. However, his ideas are sources of enduring controversies in both scientific and theological circles. Here I uncover some of the core reasons (...) why his ways of thinking and writing are often problematic, and propose a way forward. This note aims to introduce Teilhard’s central article about the noosphere, but can also be read as an independent introduction to Teilhard’s system of thought. A detailed exegesis of Teilhard’s article is available as a supplementary document. (shrink)

A notion of delegated causality is introduced here. This subtle kind of causality is dual to interventional causality. Delegated causality elucidates the causal role of dynamical systems at the “edge of chaos”, explicates evident cases of downward causation, and relates emergent phenomena to Gödel’s incompleteness theorem. Apparently rich implications are noticed in biology and Chinese philosophy. The perspective of delegated causality supports cognitive interpretations of self-organization and evolution.

Darwin provided us with a powerful theoretical framework to explain the evolution of living systems. Natural selection alone, however, has sometimes been seen as insufficient to explain the emergence of new levels of selection. The problem is one of “circularity” for evolutionary explanations: how to explain the origins of Darwinian properties without already invoking their presence at the level they emerge. That is, how does evolution by natural selection commence in the first place? Recent results in experimental evolution suggest a (...) way forward: Paul Rainey and his collaborators have shown that Darwinian properties could be exogenously imposed via what they call “ecological scaffolding.” This could solve the “black box” dilemma faced by Darwinian explanations of new levels of organization. Yet, despite “scaffolding” recently becoming a popular term in the study of cognition, culture, and evolution, the concept has suffered from vagueness and ambiguity. This article aims to show that scaffolding can be turned into a proper scientific concept able to do explanatory work within the context of the major evolutionary transitions. Doing so will allow us to once again extend the scope of the Darwinian model of evolution by natural selection. (shrink)

Industrial melanism, according to the traditional explanation, amounts to niche construction since it involves changes in predation pressure. Indeed, it would be difficult to imagine selection without niche construction. This cannot be what Laland, Odling-Smee & Feldman mean. They offer convincing examples, but they should provide a better definition of “niche construction” to indicate how their view supplements traditional evolutionary biology.

Wilson & Sober's discussion of group selection is marred by the absence of plausible examples of human group-level behavioral adaptation. The trait of authoritarianism is one possible example of such an adaptation. It reduces within-group variance in reproductive success, manifests itself more strongly in response to group-level threat, and is found in a variety of cultures.

Abstract.Human altruistic behavior has received a great deal of scientific attention over the past forty years. Altruistic‐like behaviors found among insects and animals have illumined certain human behaviors, and the revival of interest in group selection has focused attention on how sacrificial altruism, although not adaptive for individuals, can be adaptive for groups. Curiously, at the same time that sociobiology has placed greater emphasis on the value of sacrificial altruism, Protestant ethics in America has moved away from it. While Roman (...) Catholic ethics has a longstanding tradition emphasizing an ordering of love, placing love of self second only to love for God, Protestant ethics in America has adopted a similar stance only recently, replacing a strong sacrificial ethic with one focusing on mutual regard for self and others. If sociobiology is correct about the significance of sacrificial altruistic behaviors for the survival of communities, this shift away from sacrificial agape by American Christianity may cut the community off from important resources for the development of a global ethic crucial for the survival of that faith community and humankind itself. (shrink)

Human altruistic behavior has received a great deal of scientific attention over the past forty years. Altruistic-like behaviors found among insects and animals have illumined certain human behaviors, and the revival of interest in group selection has focused attention on how sacrificial altruism, although not adaptive for individuals, can be adaptive for groups. Curiously, at the same time that sociobiology has placed greater emphasis on the value of sacrificial altruism, Protestant ethics in America has moved away from it. While Roman (...) Catholic ethics has a longstanding tradition emphasizing an ordering of love, placing love of self second only to love for God, Protestant ethics in America has adopted a similar stance only recently, replacing a strong sacrificial ethic with one focusing on mutual regard for self and others. If sociobiology is correct about the significance of sacrificial altruistic behaviors for the survival of communities, this shift away from sacrificial agape by American Christianity may cut the community off from important resources for the development of a global ethic crucial for the survival of that faith community and humankind itself. (shrink)

The evolutionist challenge to moral realism is the skeptical challenge that, if evolution is true, it would only be by chance, a “happy coincidence” as Sharon Street puts it, if human moral beliefs were true. The author formulates Street’s “happy coincidence” argument more precisely using a distinction between probabilistic sensitivity and insensitivity introduced by Elliott Sober. The author then considers whether it could be rational for us to believe that human moral judgments about particular cases are probabilistically sensitive to strongly (...) universal fundamental moral standards of cooperation and fair division. The author provides an explanation of why there would be a benign correlation between human moral judgments in particular cases and the requirements of strongly universal fundamental moral standards. The explanation of the benign correlation is based on group selection for groups of individuals with an egalitarian satisficing psychology and egalitarian norms, because of the ability of such groups to more efficiently solve gene-propagation collective action problems. (shrink)

This paper surveys recent philosophy of biology. It aims to introduce outsiders to the field to the recent literature (which is reviewed in the footnotes) and the main recent debates. I concentrate on three of these: recent critiques of the replicator/vehicle distinction and its application to the idea of the gene as the unit of section; the recent defences of group selection and the idea that standard alternatives to group selection are in fact no more than a disguised form of (...) group selection; and recent ideas on the role of selection in evolution, especially the role of selection in structuring the large-scale history of life. The paper connects philosophy of biology to some more general problems in the philosophy of science, and concludes with a few suggestions about unfinished business. (shrink)

Once upon a time in evolutionary theory, everything happened for the best. Predators killed only the old or the sick. Pecking orders and other dominance hierarchies minimized wasteful conflict within the group. Male displays ensured that only the best and the fittest had mates. In the culmination of this tradition, Wynne-Edwards argued that many species have mechanisms that ensure groups do not over-exploit their resource base. The “central function” of territoriality in birds and other higher animals is “of limiting the (...) numbers of occupants per unit area of habitat”. Species with dominance hierarchies, species with lekking breeding systems, and species with communal breeding regulate their populations. These social mechanisms have population regulation as their “underlying primary function”. Wynne-Edwards argued that these mechanisms evolve through group selection. Populations without such mechanisms are apt to go extinct by eroding their own resource base. (shrink)

Biologists rely extensively on the iterated Prisoner's Dilemma game to model reciprocal altruism. After examining the informal conditions necessary for reciprocal altruism, I argue that formal games besides the standard iterated Prisoner's Dilemma meet these conditions. One alternate representation, the modified Prisoner's Dilemma game, removes a standard but unnecessary condition; the other game is what I call a Cook's Dilemma. We should explore these new models of reciprocal altruism because they predict different stability characteristics for various strategies; for instance, I (...) show that strategies such as Tit-for-Tat have different stability dynamics in these alternate models. (shrink)

Genic selectionism holds that all selection can be understood as operating on particular genes. Critics (and conventional biological wisdom) insist that this misrepresents the actual causal structure of selective phenomena at higher levels of biological organization, but cannot convincingly defend this intuition. I argue that the real failing of genic selectionism is pragmatic – it prevents us from adopting the most efficient corpus of causal laws for predicting and intervening in the course of affairs – and I offer a Pragmatic (...) account of causation itself which ultimately bears out the claim that genic selectionism misrepresents the causal structure of selective contexts. (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.

Many of the most important properties of human groups – including properties that may give one group an evolutionary advantage over another – are properly defined only at the level of group organization. Yet at present, most work on the evolution of culture has focused solely on the transmission of individual-level traits. I propose a conceptual extension of the theory of cultural evolution, particularly related to the evolutionary competition between cultural groups. The key concept in this extension is the emergent (...) group-level trait. This type of trait is characterized by the structured organization of differentiated individuals and constitutes a unit of selection that is qualitatively different from selection on groups as defined by traditional multilevel selection theory. As a corollary, I argue that the traditional focus on cooperation as the defining feature of human societies has missed an essential feature of cooperative groups. Traditional models of cooperation assume that interacting with one cooperator is equivalent to interacting with any other. However, human groups involve differential roles, meaning that receiving aid from one individual is often preferred to receiving aid from another. In this target article, I discuss the emergence and evolution of group-level traits and the implications for the theory of cultural evolution, including ramifications for the evolution of human cooperation, technology, and cultural institutions, and for the equivalency of multilevel selection and inclusive fitness approaches. (shrink)

The scalar notion of collective intentionality has been used to characterize the evolution of largely uncollaborative apes to highly collaborative ones. This proposal covers human evolution up until and including the formation of hunter-gather groups. But can collective intentionality also explain the emergence of complex societies? I argue that it cannot. Instead of collective intentionality, collaboration in complex societies hinges on a set of non-strategic attitudes and standardized human interactions so that role divisions, institutions, norms and conventions can emerge as (...) group-level phenomena. This set, summarized as ‘conventionality’, is a product of group-level selection rather than of collectively intending minds. (shrink)

Ninety-five freshmen each recruited three peers to play a "group bidding game," an N-person prisoner’s dilemma in which anyone could win movie tickets depending on their scores in the game. Prior to playing, all participants completed a measure of prosocial value orientation. Replicating and extending earlier findings (Sheldon and McGregor 2000), our results show that prosocial participants were at a disadvantage within groups. Despite this vulnerability, prosocial participants did no worse overall than asocial participants because a counteracting group-level advantage arose (...) for prosocials, who tended to be concentrated in groups. Implications of this assortative process for the egoism/altruism debate, and for hierarchical selection theory, are discussed. (shrink)

In The Advancement of Science (1993) Philip Kitcher develops what he calls the 'Compromise Model' of the closure of scientific debates. The model is designed to acknowledge significant elements from 'Rationalist' and 'Antirationalist' accounts of science, without succumbing to the one-sidedness of either. As part of an ambitious naturalistic account of scientific progress, Kitcher's model succeeds to the extent that transitions in the history of science satisfy its several conditions. I critically evaluate the Compromise Model by identifying its crucial assumptions (...) and by attempting to apply the model to a major transition in the history of biology: the rejection of 'naive group selectionism' in the 1960s. I argue that the weaknesses and limitations of Kitcher's model exemplify general problems facing philosophical models of scientific change, and that recognition of these problems supports a more modest vision of the relationship between historical and philosophical accounts of science. (shrink)

Evolutionary psychologists argue that selective pressures in our ancestral environment yield a highly specialized set of modular cognitive capacities. However, recent papers in developmental psychology and neuroscience claim that evolutionary accounts of modularity are incompatible with the flexibility and plasticity of the developing brain. Instead, they propose cortical and neuronal brain structures are fixed through interactions with our developmental environment. Buller and Gray Hardcastle contend that evolutionary accounts of cognitive development are unacceptably rigid in light of evidence of cortical plasticity. (...) The developing structure of the brain is both too random and too sensitive to external stimuli to be the product of a fixed genetic mechanism. They also claim that the complexity of the human brain cannot be explained in terms of our meager genetic endowment. There simply are not enough genes to program the intricate neuronal structures that are essential to cognition. I argue that neither of these arguments are persuasive. Small numbers of genes can function to determine diverse phenotypical outcomes through evolutionarily selected developmental systems. Similarly, theories of modularity do not rule out the possibility that innate cognitive systems exploit environmental regularities to guide the developing structure of the brain. Consequently, the anti-adaptionist consequences of these positions should be rejected. (shrink)

Humans are often altruistic in a variety of contexts, even toward strangers they may never meet again. What explains this behavior? Many argue that kin selection cannot explain it but group selecti...

Runaway social selection resulting from partner choice may have shaped aspects of human cooperation and complex sociality that are otherwise hard to account for. Social selection is the subtype of natural selection that results from the social behaviors of other individuals. Competition to be chosen as a social partner can, like competition to be chosen as a mate, result in runaway selection that shapes extreme traits. People prefer partners who display valuable resources and bestow them selectively on close partners. The (...) resulting phenotypic covariance between displays and preferences gives fitness advantages to both, creating runaway selection that could shape a whole suite of prosocial traits including altruism, moral capacities, empathy, and theory of mind. Even though they give a net fitness benefit, traits at the endpoint of runaway social selection can have substantial deleterious effects on other traits such as viability, ability to accumulate resources, or vulnerability to mental disorders. Social selection forces arising from self-interested partner choices may be an invisible hand that shaped capacities for commitment, altruism, and other prosocial capacities of the human social brain. (shrink)

Humans appear to be possible candidates for group selection because they are often said to live in bands, clans, and tribes. These terms, however, are only names for conceptual categories of people. They do not designate enduring bounded gatherings of people that might be “vehicles of selection.” Hence, group selection has probably not been a major force in human evolution.

The project is to traverse with quite novel questions, and as though with new eyes, the enormous, distant, and so well hidden land of morality—of morality that has actually existed, actually been lived.This essay offers a contribution to the consilience of the humanities, social sciences, and life sciences in accord with naturalism (in a spirit closer to Slingerland 2008 than Wilson 1998). Human beings have a shared nature produced by evolutionary history and modified by culture, where 'culture' refers to "information (...) capable of affecting individuals' behavior that they acquire from other members of their species through teaching, imitation, and other forms of social transmission" (Richerson and Boyd 2005, p. 5). .. (shrink)

This chapter contains sections titled: Highlights of Past Literature Current Work Future Work.

The Problem of Biological Individuality is the problem of how to count organisms. Whilst counting organisms may seem easy, the biological world is full of difficult cases such as colonial siphonophores and aspen tree groves. One of the main solutions to the Problem of Biological Individuality is the Physiological Approach. Drawing on an argument made by Eric Olson in the personal identity debate, I argue that the Physiological Approach faces a metaphysical problem - the ‘Foetus Problem’. This paper illustrates how (...) metaphysics can contribute to debates about organisms in the philosophy of biology. (shrink)

The Problem of Biological Individuality is the problem of how to count organisms. Whilst counting organisms may seem easy, the biological world is full of difficult cases such as colonial siphonophores and aspen tree groves. One of the main solutions to the Problem of Biological Individuality is the Physiological Approach. Drawing on an argument made by Eric Olson in the personal identity debate, I argue that the Physiological Approach faces a metaphysical problem - the ‘Foetus Problem’. This paper illustrates how (...) metaphysics can contribute to debates about organisms in the philosophy of biology. (shrink)