It’s recently been argued that biological fitness can’t change over the course of an organism’s life as a result of organisms’ behaviors. However, some characterizations of biological function and biological altruism tacitly or explicitly assume that an effect of a trait can change an organism’s fitness. In the first part of the paper, I explain that the core idea of changing fitness can be understood in terms of conditional probabilities defined over sequences of events in an organism’s life. The result (...) is a notion of “conditional fitness” which is static but which captures intuitions about apparent behavioral effects on fitness. The second part of the paper investigates the possibility of providing a systematic foundation for conditional fitness in terms of spaces of sequences of states of an organism and its environment. I argue that the resulting “organism–environment history conception” helps unify diverse biological perspectives, and may provide part of a metaphysics of natural selection. (shrink)

This paper defends the position that the supposed gap between biological altruism and psychological altruism is not nearly as wide as some scholars (e.g., Elliott Sober) insist. Crucial to this defense is the use of James Mark Baldwin's concepts of “organic selection”and “social heredity” to assist in revealing that the gap between biological and psychological altruism is more of a small lacuna. Specifically, this paper argues that ontogenetic behavioral adjustments, which are crucial to individual survival and reproduction, are also crucial (...) to species survival. In particular, it is argued that human psychological altruism is produced and maintained by various sorts of mimicry and self-reflection in the aid of both individual and species survival. The upshot of this analysis is that it is possible to offer an account of psychological altruism that is closelytethered to biological altruism without reducing entirely the former to thelatter. (shrink)

In an incendiary 2010 Nature article, M. A. Nowak, C. E. Tarnita and E. O. Wilson present a savage critique of the best known and most widely used framework for the study of social evolution, W. D. Hamilton’s theory of kin selection. Over a hundred biologists have since rallied to the theory’s defence, but Nowak et al. maintain that their arguments ‘stand unrefuted’. Here I consider the most contentious claim Nowak et al. defend: that Hamilton’s rule, the core explanatory principle (...) of kin selection theory, ‘almost never holds’. I first distinguish two versions of Hamilton’s rule in contemporary theory: a special version (HRS) that requires restrictive assumptions, and a general version (HRG) that does not. I then show that Nowak et al. are most charitably construed as arguing that HRS almost never holds, while HRG buys its generality at the expense of explanatory power. While their arguments against HRS are fairly uncontroversial, their arguments against HRG are more contentious, yet these have been largely overlooked in the ensuing furore. I consider the arguments for and against the explanatory value of HRG, with a view to assessing what exactly is at stake in the debate. I suggest that the debate hinges on issues concerning the causal interpretability of regression coefficients, and concerning the explanatory function Hamilton’s rule is intended to serve. (shrink)

Andrew Bourke’s Principles of Social Evolution identifies three stages that characterize an evolutionary transition in individuality and deploys inclusive fitness theory to explain each stage. The third stage, social group transformation, has hitherto received relatively little attention from inclusive fitness theorists. In this review, I first discuss Bourke’s “virtual dominance” hypothesis for the evolution of the germ line. I then contrast Bourke’s inclusive fitness approach to the major transitions with the multi-level approach developed by Richard Michod, Samir Okasha and others. (...) I suggest that, rather than choosing between these approaches, we should exploit the strengths of both. Finally, I stress the need for a firmer conceptual grasp of the nature of social group transformation. (shrink)

Inclusive fitness theory was not originally designed to explain the major transitions in evolution, but there is a growing consensus that it has the resources to do so. My aim in this paper is to highlight, in a constructive spirit, the puzzles and challenges that remain. I first consider the distinctive aspects of the cooperative interactions we see within the most complex social groups in nature: multicellular organisms and eusocial insect colonies. I then focus on one aspect in particular: the (...) extreme redundancy these societies exhibit. I argue that extreme redundancy poses a distinctive explanatory puzzle for inclusive fitness theory, and I offer a potential solution which casts coercion as the key enabler. I suggest that the general moral to draw from the case is one of guarded optimism: while inclusive fitness is a powerful tool for understanding evolutionary transitions, it must be integrated within a broader framework that recognizes the distinctive problems such transitions present and the distinctive mechanisms by which these problems may be overcome. (shrink)

Genuine altruism would appear to be incompatible with evolutionary theory. And yet altruistic behavior would seem to occur, at least on occasion. This article first considers a game-theoretical attempt at solving this seeming paradox, before considering agroup selectionist approach. Neither approach, as they stand, would seem to render genuine, as opposed to reciprocal, altruism compatible with the theory of evolution. The article concludes by offering an alternative game-theoretical solution to the problem of altruism.

This is the introductory essay to the Italian translation of Matt Ridley's "The origins of virtue", surveying the game-theoretic and evolutionary approaches to the emergence and evolution of cooperation and altruism.

Altruism is a deep and complex phenomenon that is analysed by scholars of various disciplines, including psychology, philosophy, biology, evolutionary anthropology and experimental economics. Much confusion arises in current literature because the term altruism covers variable concepts and processes across disciplines. Here we investigate the sense given to altruism when used in different fields and argumentative contexts. We argue that four distinct but related concepts need to be distinguished: (a) psychological altruism , the genuine motivation to improve others’ interests and (...) welfare; (b) reproductive altruism , which involves increasing others’ chances of survival and reproduction at the actor’s expense; (c) behavioural altruism , which involves bearing some cost in the interest of others; and (d) preference altruism , which is a preference for others’ interests. We show how this conceptual clarification permits the identification of overstated claims that stem from an imprecise use of terminology. Distinguishing these four types of altruism will help to solve rhetorical conflicts that currently undermine the interdisciplinary debate about human altruism. (shrink)

Altruism is a malleable notion that is understood differently in various disciplines. The common denominator of most definitions of altruism is the idea of unidirectional helping behaviour. However, a closer examination reveals that the term altruism sometimes refers to the outcomes of a helping behaviour for the agent and its neighbours – i.e. reproductive altruism – and sometimes to what motivates the agent to help others – i.e. psychological altruism. Since these perspectives on altruism are crucially different, it is important (...) to use a clear terminology to avoid confusion. In particular, we show that the notion of altruism used by biologists profoundly differs from the ones used by philosophers, psychologists and economists in cross-disciplinary debates about human altruism. (shrink)

Contemporary philosophers and psychologists seek the roots of ethically sound forms of behavior, including altruism and a sense of fairness, in the basic structure of cooperative action. I argue that recent work on cooperation in both philosophy and psychology has been hampered by what I call “the mutualistic paradigm.” The mutualistic paradigm treats one kind of cooperative situation—what I call a “mutualistic situation”—as paradigmatic of cooperation in general. In mutualistic situations, such as the primeval stag hunt described by Brian Skyrms, (...) every partner in a cooperative action has to do his part in order for the action as a whole to succeed. But many familiar cooperative situations—for example, serving on an academic committee—do not have this structure. Contemporary philosophers and psychologists are right that thinking about cooperation can shed light on how and why ethically sound behavior happens in human beings. But the deep connections between ethics and cooperation only come into view once we have a richer conception of our capacities for cooperation than the mutualistic paradigm provides. (shrink)

In what follows, I critique the interpretation that Sober and Wilson offer of their group selection model in Unto Others. Sober and Wilson mistakenly claim that their model operates as an example of Simpson's paradox and defend an interpretation of their model according to which groups are operated upon by natural selection. In the place of their interpretation, I offer one that parallels the mathematical calculation of the model's outcome and does not depend on the postulation of a force of (...) group selection or a value for group fitness. (shrink)

The transfer of food among group members is a ubiquitous feature of small-scale forager and forager-agricultural populations. The uniqueness of pervasive sharing among humans, especially among unrelated individuals, has led researchers to evaluate numerous hypotheses about the adaptive functions and patterns of sharing in different ecologies. This article attempts to organize available cross-cultural evidence pertaining to several contentious evolutionary models: kin selection, reciprocal altruism, tolerated scrounging, and costly signaling. Debates about the relevance of these models focus primarily on the extent (...) to which individuals exert control over the distribution of foods they acquire, and the extent to which donors receive food or other fitness-enhancing benefits in return for shares given away. Each model can explain some of the variance in sharing patterns within groups, and so generalizations that ignore or deny the importance of any one model may be misleading. Careful multivariate analyses and cross-cultural comparisons of food transfer patterns are therefore necessary tools for assessing aspects of the sexual division of labor, human life history evolution, and the evolution of the family. This article also introduces a framework for better understanding variation in sharing behavior across small-scale traditional societies. I discuss the importance of resource ecology and the degree of coordination in acquisition activities as a key feature that influences sharing behavior. Key Words: behavioral ecology; cooperation; costly signaling; food sharing; foragers; reciprocal altruism. (shrink)

1Department of Philosophy, University of Calgary, 2500 University Drive N.W., Calgary, AB T2N 1N4, 2 ´ ´ ´ Canada; Departement de Philosophie, Universite de Montreal, C.P. 6128, succursale Centre-ville.

In their recent book, Elliott Sober and David Wilson (1998) argue that evolutionary biologists have wrongly regarded kinship as the exclusive means by which altruistic behavior can evolve, at the expense of other mechanisms. I argue that Sober and Wilson overlook certain genetical considerations which suggest that kinship is likely to be a more powerful means for generating complex altruistic adaptations than the alternative mechanisms they propose.

Evolutionary applications of game theory present one of the most pedagogically accessible varieties of genuine, contemporary theoretical biology. We present here Oyun (OY-oon, http://charlespence.net/oyun), a program designed to run iterated prisoner’s dilemma tournaments, competitions between prisoner’s dilemma strategies developed by the students themselves. Using this software, students are able to readily design and tweak their own strategies, and to see how they fare both in round-robin tournaments and in “evolutionary” tournaments, where the scores in a given “generation” directly determine contribution (...) to the population in the next generation. Oyun is freely available, runs on Windows, Mac, and Linux computers, and the process of creating new prisoner’s dilemma strategies is both easy to teach and easy for students to grasp. We illustrate with two interesting examples taken from actual use of Oyun in the classroom. (shrink)

When game theory was introduced to biology, the components of classic game theory models were replaced with elements more befitting evolutionary phenomena. The actions of intelligent agents are replaced by phenotypic traits; utility is replaced by fitness; rational deliberation is replaced by natural selection. In this paper, I argue that this classic conception of comprehensive reapplication is misleading, for it overemphasizes the discontinuity between human behavior and evolved traits. Explicitly considering the representational roles of evolutionary game theory brings to attention (...) neglected areas of overlap, as well as a range of evolutionary possibilities that are often overlooked. The clarifications this analysis provides are well-illustrated by—and particularly valuable for—game theoretic treatments of the evolution of social behavior. (shrink)

Many situations in human life present choices between (a) narrowly preferred particular alternatives and (b) narrowly less preferred (or aversive) particular alternatives that nevertheless form part of highly preferred abstract behavioral patterns. Such alternatives characterize problems of self-control. For example, at any given moment, a person may accept alcoholic drinks yet also prefer being sober to being drunk over the next few days. Other situations present choices between (a) alternatives beneficial to an individual and (b) alternatives that are less beneficial (...) (or harmful) to the individual that would nevertheless be beneficial if chosen by many individuals. Such alternatives characterize problems of social cooperation; choices of the latter alternative are generally considered to be altruistic. Altruism, like self-control, is a valuable temporally-extended pattern of behavior. Like self-control, altruism may be learned and maintained over an individual's lifetime. It needs no special inherited mechanism. Individual acts of altruism, each of which may be of no benefit (or of possible harm) to the actor, may nevertheless be beneficial when repeated over time. However, because each selfish decision is individually preferred to each altruistic decision, people can benefit from altruistic behavior only when they are committed to an altruistic pattern of acts and refuse to make decisions on a case-by-case basis. (shrink)

Altruism is a central concept in evolutionary biology. Evolutionary biologists still disagree about its meaning (E.O. Wilson 2005; Fletcher et al. 2006; D.S. Wilson 2008; Foster et al. 2006a, b; West et al. 2007a, 2008). Semantic disagreement appears to be quite robust and not easily overcome by attempts at clarification, suggesting that substantive conceptual issues lurk in the background. Briefly, group selection theorists define altruism as any trait that makes altruists losers to selfish traits within groups, and makes groups of (...) altruists fitter than groups of non-altruists. Inclusive fitness theorists reject a definition based on within- and between-group fitness. Traits are altruistic only if they cause a direct and absolute fitness loss to the donor. The latter definition is more restrictive and rejects as cases of altruism behaviors that are accepted by the former. Fletcher and Doebeli (2009) recently proposed a simple, direct and individually based fitness approach, which they claim returns to first principles: carriers of the genotype of interest “must, on average, end up with more net direct fitness benefits than average population members.” This seductively simple proposal uses the concept of assortment to explain how diverse kinds of altruists end up on average with more net fitness than their non-altruistic rivals. In this paper I shall argue that their approach implies a new concept of altruism that contrasts with and improves on the concept of the inclusive fitness approach. (shrink)

Views on the evolution of altruism based upon multilevel selection on structured populations pay little attention to the difference between fortuitous and deliberate processes leading to assortative grouping. Altruism may evolve when assortative grouping is fortuitously produced by forces external to the organism. But when it is deliberately produced by the same proximate mechanism that controls altruistic responses, as in humans, exploitation of altruists by selfish individuals is unlikely and altruism evolves as an individually advantageous trait. Groups formed with altruists (...) of this sort are special, because they are not affected by subversion from within. A synergistic process where altruism is selected both at the individual and at the group level can take place. (shrink)

Los sociobiólogos han defendido una posición "calvinista" que se resume en la siguiente fórmula: si la selección natural explica las actitudes morales, no hay altruismo genuino en la moral; si la moral es altruista, entonces la selección natural no puede explicarla. En este ensayo desenmascaro los presupuestos erróneos de esta posición y defiendo que el altruismo como equidad no es incompatible con la selección natural. Rechazo una concepción hobbesiana de la moral, pero sugiero su empleo en la interpretación de la (...) psicología de los primates no humanos y en un modelo de progresión evolutiva que habría llevado a la moralidad como adaptación pasando por la razón instrumental. /// Sociobiologists have endorsed a "Calvinist" position captured in the following formula: if natural selection explains moral attitudes, morality is not genuinely altruistic; if morality is altruistic, then natural selection cannot explain it. I expose the false presuppositions behind this claim and argüe that altruism as fairness is not incompatible with natural selection. I reject a Hobbesian view of morality as an instrumental endorsement of fairness norms, but suggest its use to interpret primate psychology and to model an evolutionary progression ending in moral capacities as adaptations. (shrink)

A simple and general criterion is derived for the evolution of altruism when individuals interact in pairs. It is argued that the treatment of this problem in kin selection theory and in game theory are special cases of this general criterion.

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)

No matter what we do, however kind or generous our deeds may seem, a hidden motive of selfishness lurks--or so science has claimed for years. This book, whose publication promises to be a major scientific event, tells us differently. In Unto Others philosopher Elliott Sober and biologist David Sloan Wilson demonstrate once and for all 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 insects that subsume themselves in the superorganism of a colony to the human capacity for selflessness--even as it explains the evolutionary sense of such behavior. (shrink)

Psychological altruism (being motivated by the needs of others) has a tendency to produce behaviour that is costly in evolutionary terms. How, then, could the capacity for psychological altruism evolve? One suggestion is that it is the result of sexual selection. There are, however, two problems that face such an account: first, it is not clear that the resulting behaviour would be altruistic in the relevant sense, and second, it does not seem to fit with key features of our actual (...) helping behaviour. I will argue that both of these problems can be avoided if we adopt a modular account of desire formation. (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)