Individual-as-maximizing agent analogies result in a simple understanding of the functioning of the biological world. Identifying the conditions under which individuals can be regarded as fitness maximizing agents is thus of considerable interest to biologists. Here, we compare different concepts of fitness maximization, and discuss within a single framework the relationship between Hamilton’s (J Theor Biol 7:1–16, 1964) model of social interactions, Grafen’s (J Evol Biol 20:1243–1254, 2007a) formal Darwinism project, and the idea of evolutionary stable strategies. We (...) distinguish cases where phenotypic effects are additive separable or not, the latter not being covered by Grafen’s analysis. In both cases it is possible to define a maximand, in the form of an objective function ϕ(z), whose argument is the phenotype of an individual and whose derivative is proportional to Hamilton’s inclusivefitness effect. However, this maximand can be identified with the expression for fecundity or fitness only in the case of additive separable phenotypic effects, making individual-as-maximizing agent analogies unattractive (although formally correct) under general situations of social interactions. We also feel that there is an inconsistency in Grafen’s characterization of the solution of his maximization program by use of inclusivefitness arguments. His results are in conflict with those on evolutionary stable strategies obtained by applying inclusivefitness theory, and can be repaired only by changing the definition of the problem. (shrink)
This paper attempts to reconcile critics and defenders of inclusivefitness by constructing a synthesis that does justice to the insights of both. I argue that criticisms of the regression-based version of Hamilton’s rule, although they undermine its use for predictive purposes, do not undermine its use as an organizing framework for social evolution research. I argue that the assumptions underlying the concept of inclusivefitness, conceived as a causal property of an individual organism, are unlikely (...) to be exactly true in real populations, but they are approximately true given a specific type of weak selection that Hamilton took, on independent grounds, to be responsible for the cumulative assembly of complex adaptation. Finally, I reflect on the uses and limitations of “design thinking” in social evolution research. The debate about the foundations of inclusivefitness theory that has followed in the wake of Nowak, Tarnita and Wilson’s critique has been remarkably polarizing. After several rounds of rebuttals and replies, there is still little evidence of any serious reconciliation between the theory’s critics and its defenders. It doesn’t have to be this way. I believe that, on the main points of disagreement, it is possible to find a way forward that does justice to the insights of both camps. My aim in this paper is to find that way forward. (shrink)
Inclusivefitness theory provides conditions for the evolutionary success of a gene. These conditions ensure that the gene is selfish in the sense of Dawkins (The selfish gene, Oxford University Press, Oxford, 1976): genes do not and cannot sacrifice their own fitness on behalf of the reproductive population. Therefore, while natural selection explains the appearance of design in the living world (Dawkins in The blind watchmaker: why the evidence of evolution reveals a universe without design, W. W. (...) Norton, New York, 1996), inclusivefitness theory does not explain how. Indeed, Hamilton’s rule is equally compatible with the evolutionary success of prosocial altruistic genes and antisocial predatory genes, whereas only the former, which account for the appearance of design, predominate in successful organisms. Inclusivefitness theory, however, permits a formulation of the central problem of sociobiology in a particularly poignant form: how do interactions among loci induce utterly selfish genes to collaborate, or to predispose their carriers to collaborate, in promoting the fitness of their carriers? Inclusivefitness theory, because it abstracts from synergistic interactions among loci, does not answer this question. Fitness-enhancing collaboration among loci in the genome of a reproductive population requires suppressing alleles that decrease, and promoting alleles that increase the fitness of its carriers. Suppression and promotion are effected by regulatory networks of genes, each of which is itself utterly selfish. This implies that genes, and a fortiori individuals in a social species, do not maximize inclusivefitness but rather interact strategically in complex ways. It is the task of sociobiology to model these complex interactions. (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. Inclusivefitness 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 inclusivefitness approach. (shrink)
Grouping severe mental disorders into a global category is likely to lead to a “theory of everything” which forcefully explains everything and nothing. Speculation even at the phenotypic level of the single disorder cannot be fruitful, unless specific and testable models are proposed. Inclusivefitness must be incorporated in such models. (Published Online November 9 2006).
This article analyzes the recent debate surrounding inclusivefitness and argues that certain limitations ascribed to it by critics—such as requiring weak selection or providing dynamically insufficient models—are better thought of as limitations of the methodological framework most often used with inclusivefitness. In support of this, I show how inclusivefitness can be used with the replicator dynamics. I conclude that much of the debate is best understood as being about the orthogonal issue (...) of using abstract versus idealized models. (shrink)
ABSTRACT In social evolution theory, biological individuals are often represented on the model of rational agents, that is, as if they were ‘seeking’ to maximize their own reproductive success. In the 1990s, important criticisms of this mode of thinking were made by Brian Skyrms and Elliott Sober, who both argued that ‘rational agent’ models can lead to incorrect predictions when there are positive correlations between individuals’ phenotypes. In this article, I argue that one model of rational choice—namely, Savage’s model —can (...) actually be vindicated in evolutionary biology, provided that the pay-offs are computed in inclusivefitness terms. I also show that the use of this model is better avoided when pay-offs are non-additive, or when certain causal influences affect the outcome of natural selection. The result is a partial rehabilitation of this mode of thinking, conditional on both the additivity of the pay-off structure and the absence of any form of manipulation or coercion. _1_ Introduction _2_ When Natural Selection and Rational Deliberation Part Ways _3_ A Simple Solution: Redefining the Pay-offs in InclusiveFitness Terms _4_ Sober on InclusiveFitness Maximization _5_ InclusiveFitness with Non-additive Pay-offs _6_ Causal Influences and the Savage– Hamilton Model _6.1_ Reciprocity and partner choice _6.2_ Coercion and manipulation _7_ Conclusion Appendix. (shrink)
Hamilton’s theory of inclusivefitness is a widely used framework for studying the evolution of social behavior, but controversy surrounds its status. Hamilton originally derived his famous rb > c rule for the spread of a social gene by assuming additivity of costs and benefits. However, it has recently been argued that the additivity assumption can be dispensed with, so long as the −c and b terms are suitably defined, as partial regression coefficients. I argue that this way (...) of generalizing Hamilton’s rule to the nonadditive case, while formally correct, faces conceptual problems. (shrink)
Philosophers have shown that the Aristotelian conception of mind and body is capable of resolving the problems confronting dualism. In this paper the resolution of the mind–body problem is extended with a scientific solution by integrating the Aristotelian framework with evolutionary theory. It is discussed how the theories of Fisher and Hamilton enable us to construct and solve hypotheses about how the mind evolved out of matter. These hypotheses are illustrated by two examples: the evolutionary transition from cells to multicellular (...) organisms, and the evolutionary transition from babbling to doing things with words and later reasoning and giving reasons. The first transitions resulted in the sensitive psyche of the other animals, the second in the rational psyche of humans. It is discussed how exploratory behaviour of lower-level entities facilitated these evolutionary transitions. (shrink)
We show how Richard Jeffrey’s The Logic of Decision provides the proper formalism for calculating expected fitness for correlated encounters in general. As an illustration, some puzzles about kin selection are resolved.
We show how Richard Jeffrey’s The Logic of Decision provides the proper formalism for calculating expected fitness for correlated encounters in general. As an illustration, some puzzles about kin selection are resolved.
Hamilton introduced two conceptions of social fitness, which he called neighbour-modulated fitness and inclusivefitness. Although he regarded them as formally equivalent, a re-analysis of his own argument for their equivalence brings out two important assumptions on which it rests: weak additivity and actor's control. When weak additivity breaks down, neither fitness concept is appropriate in its original form. When actor's control breaks down, neighbour-modulated fitness may be appropriate, but inclusivefitness is (...) not. Yet I argue that, despite its more limited domain of application, inclusivefitness provides a distinctively valuable perspective on social evolution. (shrink)
Two questions are raised for Grafen’s formal darwinism project of aligning evolutionary dynamics under natural selection with the optimization of phenotypes for individuals of a population. The first question concerns mean fitness maximization during frequency-dependent selection; in such selection regimes, not only is mean fitness typically not maximized but it is implausible that any parameter closely related to fitness is being maximized. The second question concerns whether natural selection on inclusivefitness differences can be regarded (...) as individual selection or whether it leads to a departure from the central motivation that led to the formal darwinism project, viz., to show that “Darwinian” evolution through individual selection leads to “good design” or phenotypic adaptation through trait optimization. (shrink)
I argue that Grafen’s formal darwinism project could profitably incorporate a gene’s-eye view, as informed by the major transitions framework. In this, instead of the individual being assumed to maximise its inclusivefitness, genes are assumed to maximise their inclusivefitness. Maximisation of fitness at the individual level is not a straightforward concept because the major transitions framework shows that there are several kinds of biological individual. In addition, individuals have a definable fitness, exhibit (...) individual-level adaptations and arise in a major transition, only to the extent that the inclusive-fitness interests of genes within them coincide. Therefore, as others have suggested, the fundamental level at which fitness is maximised is the gene level. Previous reconciliations of the concepts of gene-level fitness and individual-level fitness implicitly recognise this point. Adaptations always maximise the fitness of their causative genes, but may be simple or complex. Simple adaptations may be controlled by single genes and be maladaptive at higher levels, whereas complex adaptations are controlled by multiple genes and rely on those genes having coinciding fitness interests at a higher level, for a given trait. (shrink)
Hamilton’s theory of kin selection is the best-known framework for understanding the evolution of social behavior but has long been a source of controversy in evolutionary biology. A recent critique of the theory by Nowak, Tarnita, and Wilson sparked a new round of debate, which shows no signs of abating. In this overview, we highlight a number of conceptual issues that lie at the heart of the current debate. We begin by emphasizing that there are various alternative formulations of Hamilton’s (...) rule, including a general version, which is always true; an proximate version, which assumes weak selection; and a special version, which demands other restrictive assumptions. We then examine the relationship between the neighbor-modulated fitness and inclusivefitness approaches to kin selection. Finally, we consider the often-strained relationship between the theories of kin and multilevel selection. (shrink)
Cooperation is rife in the microbial world, yet our best current theories of the evolution of cooperation were developed with multicellular animals in mind. Hamilton’s theory of inclusivefitness is an important case in point: applying the theory in a microbial setting is far from straightforward, as social evolution in microbes has a number of distinctive features that the theory was never intended to capture. In this article, I focus on the conceptual challenges posed by the project of (...) extending Hamilton’s theory to accommodate the effects of gene mobility. I begin by outlining the basics of the theory of inclusivefitness, emphasizing the role that the concept of relatedness is intended to play. I then provide a brief history of this concept, showing how, over the past fifty years, it has departed from the intuitive notion of genealogical kinship to encompass a range of generalized measures of genetic similarity. I proceed to argue that gene mobility forces a further revision of the concept. The reason in short is that, when the genes implicated in producing social behaviour are mobile, we cannot talk of an organism’s genotype simpliciter; we can talk only of an organism’s genotype at a particular stage in its life cycle. We must therefore ask: with respect to which stage(s) in the life cycle should relatedness be evaluated? For instance: is it genetic similarity at the time of social interaction that matters to the evolution of social behaviour, or is it genetic similarity at the time of reproduction? I argue that, strictly speaking, it is neither of these: what really matters to the evolution of social behaviour is diachronic genetic similarity between the producers of fitness benefits at the time they produce them and the recipients of those benefits at the end of their life-cycle. I close by discussing the implications of this result. The main payoff is that it makes room for a possible new mechanism for the evolution of altruism in microbes that does not require correlated interaction among bearers of the genes for altruism. The importance of this mechanism in nature remains an open empirical question. (shrink)
When we have asked Hadza whether married couples should live with the family of the wife (uxorilocally) or the family of the husband (virilocally), we are often told that young couples should spend the first years of a marriage living with the wife’s family, and then later, after a few children have been born, the couple has more freedom—they can continue to reside with the wife’s kin, or else they could join the husband’s kin, or perhaps live in a camp (...) where there are no close kin. In this paper, we address why shifts in kin coresidence patterns may arise in the later years of a marriage, after the birth of children. To do so, we model the inclusivefitness costs that wives might experience from leaving their own kin and joining their husband’s kin as a function of the number of children in their nuclear family. Our model suggests that such shifts should become less costly to wives as their families grow. This simple model may help explain some of the dynamics of postmarital residence among the Hadza and offer insight into the dynamics of multilocal residence, the most prevalent form of postmarital residence among foragers. (shrink)
The kinship theory of genomic imprinting predicts that imprinted genes affect parent–child and child–child interactions. During prenatal and neonatal stages, patrigenes promote selfish and matrigenes altruistic behavior. Models predict that this imprinted gene expression pattern is reversed starting with the juvenile stage. This article explores possible effects of imprinted genes on nonverbal and simple and complex linguistic behaviors before and after the reversal. A hypothesis is discussed that is based on the observation language evolved as a new form of communicative (...) behavior. Inclusivefitness theory is used for explaining how and why new forms of communicative behaviors evolved as an extension of behaviors and gestures displayed by our predecessors. The hypothesis is elaborated through discussing a scenario of early language evolution. This scenario is used for explaining early stages in child development and for discussing possible effects of patrigenes and matrigenes on the development of children’s communicative behaviors. (shrink)
Phenomena like meat sharing in hunter-gatherers, altruistic self-sacrifice in intergroup conflicts, and contribution to the production of public goods in laboratory experiments have led to the development of numerous theories trying to explain human prosocial preferences and behavior. Many of these focus on direct and indirect reciprocity, assortment, or (cultural) group selection. Here, I investigate analytically how genetic relatedness changes the incentive structure of that paradigmatic game which is conventionally used to model and experimentally investigate collective action problems: the public (...) goods game. Using data on contemporary hunter-gatherer societies I then estimate a threshold value determining when biological altruism turns into maximizing inclusivefitness in this game. I find that, on average, contributing no less than about 40% of individual fitness to public goods production still is an optimal strategy from an inclusivefitness perspective under plausible socio-ecological conditions. (shrink)
Supporting Hamilton’s inclusivefitness theory, archival analyses of inheritance patterns in wills have revealed that people invest more of their estates in kin of closer genetic relatedness. Recent classroom experiments have shown that this genetic relatedness effect is stronger for relatives of direct lineage (children, grandchildren) than for relatives of collateral lineage (siblings, nieces, nephews). In the present research, multilevel modeling of more than 1,000 British Columbian wills revealed a positive effect of genetic relatedness on proportions of estates (...) allocated to relatives. This effect was qualified by an interaction with lineage, such that it was stronger for direct than for collateral relatives. Exploratory analyses of the moderating role of benefactors’ sex and estate values showed the genetic relatedness effect was stronger among female and wealthier benefactors. The importance of these moderators to understanding kin investment in modern humans is discussed. (shrink)
This paper addresses methodological and metatheoretical aspects of the ongoing debate over the adaptive significance of Tibetan polyandry. Methodological contributions include a means of estimating relatedness of fraternal co-husbands given multigenerational polyandry, and use of Hamilton’s rule and a member-joiner model to specify how inclusivefitness gains of co-husbands may vary according to seniority, opportunity costs, and group size. These methods are applied to various data sets, particularly that of Crook and Crook (1988). The metatheoretical discussion pivots on (...) the critique by evolutionary psychologists of adaptationist accounts of polyandry. Contrary to this critique, I argue that valid adaptationist explanations of such practices do not necessitate cognitive mechanisms evolved specifically to produce polyandry, nor that there must have been exact equivalents of Tibetan agricultural estates and social institutions in human evolutionary history. Specific issues raised when one posits either kin selection or cultural evolution to explain the adaptive features of Tibetan polyandry are also discussed. (shrink)
Phenomena like meat sharing in hunter-gatherers, self-sacrifice in intergroup conflicts, and voluntary contribution to public goods provision in laboratory experiments have led to the development of numerous theories on the evolution of altruistic in-group beneficial behavior in humans. Many of these theories abstract away from the effects of kinship on the incentives for public goods provision, though. Here, it is investigated analytically how genetic relatedness changes the incentive structure of that paradigmatic game which is conventionally used to model and experimentally (...) investigate collective action problems: the linear public goods game. Using recent anthropological data sets on relatedness in 61 contemporary hunter-gatherer and horticulturalist societies the relevant parameters of this model are then estimated. It turns out that the kinship patterns observed in these societies substantially reduce the negative effect of increasing group size on incentives for public goods provision. It is suggested, therefore, that renewed attention should be given to inclusivefitness theory in the context of public goods provision also in sizable groups, because its explanatory power with respect to this central problem in the evolution of human cooperativeness and altruism might have been substantially underrated. (shrink)
Two predictions concerning the perceived severity of crimes can be derived from evolutionary theory. The first, arising from the theory of inclusivefitness, is that crimes in general should be viewed as more serious to the degree that the victim is genetically related to the perpetrator. The second, arising from the deleterious effects of inbreeding depression, is that heterosexual sexual coercion should be perceived as more serious the closer the genetic relationship of victim and perpetrator, particularly when the (...) victim is a female of fertile age. Two hundred and thirty university students estimated the magnitude of the severity of brief crime descriptions in three separate studies. In the first two, the biological kinship of victim and perpetrator was varied, and in the third, the hypothetical genetic relatedness of the subject and the fictitious victim was varied. All three studies found the linear relationships between biological kinship and perceived crime severity predicted by theory. (shrink)
From mitochondria to meerkats, the natural world is full of spectacular examples of social behaviour. In the early 1960s W. D. Hamilton changed the way we think about how such behaviour evolves. He introduced three key innovations - now known as Hamilton's rule, kin selection, and inclusivefitness - and his pioneering work kick-started a research program now known as social evolution theory. This is a book about the philosophical foundations and future prospects of that program.
Following Wallace’s suggestion, Darwin framed his theory using Spencer’s expression “survival of the fittest”. Since then, fitness occupies a significant place in the conventional understanding of Darwinism, even though the explicit meaning of the term ‘fitness’ is rarely stated. In this paper I examine some of the different roles that fitness has played in the development of the theory. Whereas the meaning of fitness was originally understood in ecological terms, it took a statistical turn in terms (...) of reproductive success throughout the 20th Century. This has lead to the ever-increasing importance of sexually reproducing organisms and the populations they compose in evolutionary explanations. I will argue that, moving forward, evolutionary theory should look back at its ecological roots in order to be more inclusive in the type of systems it examines. Many biological systems can only be satisfactorily accounted for by offering a non-reproductive account of fitness. This argument will be made by examining biological systems with very small or transient population structures. I argue this has significant consequences for how we define Darwinism, increasing the significance of survival over that of reproduction. (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. More than 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)
Given the recent explosion of interest in applications of evolutionary biology to understanding human psychology, we think it timely to assure better understanding of modern evolutionary theory among the psychologists who might be using it. We find it necessary to do so because of the very reducd version of evolutionary theorizing that has been incorporated into much of evolutionary psychology so far. Our aim here is to clarify why the use of a reduced version of evolutionary genetics will lead to (...) faulty science and to indicate where other resources of evolutionary biology can be found that might elevate the standard of the evolutionary component of evolutionary psychology. (shrink)
The Formal Darwinism project probes the connections between the dynamics of natural selection and the design of organisms. Here, I explain why this work should be of interest to philosophers, arguing that it is the natural development in a long-running scholarly enquiry into the meaning of life. I then review some of my own work which has applied the tools of Formal Darwinism to address issues concerning the units of adaptation in social evolution, leading to a deeper understanding of the (...) adaptation of individual organisms. Finally, I sketch some directions Formal Darwinism to explore beyond the biological sciences, with a focus upon cosmology. (shrink)
Various results show the ‘formal equivalence’ of kin and group selectionist methodologies, but this does not preclude there being a real and useful distinction between kin and group selection processes. I distinguish individual and population-centred approaches to drawing such a distinction, and I proceed to develop the latter. On the account I advance, the differences between kin and group selection are differences of degree in the structural properties of populations. A spatial metaphor provides a useful framework for thinking about these (...) differences: kin and group selection may be conceptualized as large, overlapping regions of K-G space. I then consider some implications of the account, defend it from possible objections, and further argue that the structural features characteristic of both kin and group selection may recur at multiple levels of biological organization. (shrink)
A study of twenty-five popular women’s novels and six famous romantic stories has led to the conclusion that such novels and stories are tales of mate selection and mating commitment. Pérusse’s (1994) predictions with respect to mate choice are confirmed by the activities of male and female protagonists in the novels (binomial test,p<.01 in all cases). Males choose mates on the basis of sexual exclusivity and fertility. Females choose mates on the basis of economic factors and parenting potential. As well, (...) male and female characters differ in terms of their display of functional emotions. (shrink)
The view that moral cognition is subserved by a two-tieredarchitecture is defended: Moral reasoning is the result both ofspecialized, informationally encapsulated modules which automaticallyand effortlessly generate intuitions; and of general-purpose,cognitively penetrable mechanisms which enable moral judgment in thelight of the agent's general fund of knowledge. This view is contrastedwith rival architectures of social/moral cognition, such as Cosmidesand Tooby's view that the mind is wholly modular, and it is argued thata two-tiered architecture is more plausible.
Una de las características del cambio científico que ofrece más resistencia a la elaboración de un modelo teórico que permita dar cuenta de él, la constituye su carácter social. Un intento importante para vencer esa resistencia, el realizado por David Hull, se apoya en la noción de adecuación inclus..
My purpose in this paper is to set forth a case for inclusion, without any restriction whatsoever, of gays and lesbians in the legal definition of marriage within the various jurisdictions within the United States of America. Historical and cross cultural definitions of marriage are usually based on two basic premises or components, structure and function. Structural definitions of marriage, with which most people and jurisdictions identify, are based on exclusion and inclusion, i.e. on who is eligible for inclusion and (...) who must be excluded. Ordinarily the restrictions exclude those not having reached the age of majority, those who are not judged mentally competent, and those of the same gender. Functional definitions of marriage are based on the willingness of the partners to engage in the duties and responsibilities to each other and to all offspring regardless of their physical or mental fitness. I intend to defend the proposition that legal marriage for gays and lesbians is better defined and defended when based on function rather than structure. Specifically, this means that marriage is the union of those who 1.) without mental equivocation embrace their mutual commitment to support and care for each other; 2.) are of legal age; 3.) are of sound mind; and 4.) affirm their commitment to fulfill, to the best of their ability, the following functions as they pertain to the natural birth, legal adoption, or foster care of any and all children included in the marital union: These functions include but are not limited to: protection , economic, affect-giving, socialization, acculturation, education, and sexual access between the conjugal partners. Historically, there is no record throughout the history of humankind, of any state or body politic that does not profess a vested interest in the mate selection patterns of its young. This is not generally for the edification of the married, but rather for the assurance of the socialization and acculturation of the ascending generation. (shrink)
We sketch a novel and improved version of Boorse’s biostatistical theory of functions. Roughly, our theory maintains that (i) functions are non-negligible contributions to survival or inclusivefitness (when a trait contributes to survival or inclusivefitness); (ii) situations appropriate for the performance of a function are typical situations in which a trait contributes to survival or inclusivefitness; (iii) appropriate rates of functioning are rates that make adequate contributions to survival or inclusive (...)fitness (in situations appropriate for the performance of that function); and (iv) dysfunction is the inability to perform a function at an appropriate rate in appropriate situations. Based on our theory, we sketch solutions to three problems that have afflicted Boorse’s theory of function, namely, Kingma’s () problem of the situation-specificity of functions, the problem of multi-functional traits, and the problem of how to distinguish between appropriate and inappropriate rates of functioning. (shrink)
There is disagreement in the literature about the exact nature of the phenomenon of empathy. There are emotional, cognitive, and conditioning views, applying in varying degrees across species. An adequate description of the ultimate and proximate mechanism can integrate these views. Proximately, the perception of an object's state activates the subject's corresponding representations, which in turn activate somatic and autonomic responses. This mechanism supports basic behaviors that are crucial for the reproductive success of animals living in groups. The Perception-Action Model, (...) together with an understanding of how representations change with experience, can explain the major empirical effects in the literature. It can also predict a variety of empathy disorders. The interaction between the PAM and prefrontal functioning can also explain different levels of empathy across species and age groups. This view can advance our evolutionary understanding of empathy beyond inclusivefitness and reciprocal altruism and can explain different levels of empathy across individuals, species, stages of development, and situations. Key Words: altruism; cognitive empathy ; comparative; emotion; emotional contagion; empathy ; evolution; human; perception-action; perspective taking. (shrink)
The function of a trait token is usually defined in terms of some properties of other (past, present, future) tokens of the same trait type. I argue that this strategy is problematic, as trait types are (at least partly) individuated by their functional properties, which would lead to circularity. In order to avoid this problem, I suggest a way to define the function of a trait token in terms of the properties of the very same trait token. To able to (...) allow for the possibility of malfunctioning, some of these properties need to be modal ones: a function of a trait is to do F just in case its doing F would contribute to the inclusivefitness of the organism whose trait it is. Function attributions have modal force. Finally, I explore whether and how this theory of biological function could be modified to cover artifact function. (shrink)
This article is primarily a study of the group selection controversy, with special emphasis on the period from 1962 to the present, and the rise of inclusivefitness theory. Interest is focused on the relations between individual fitness theory and other fitness theories and on the methodological imperatives used in the controversy over the status of these theories. An appendix formalizes the notion of "assertive part" which is used in the informal discussion of the methodological imperatives (...) elicited from the controversy. (shrink)
If someone commits the mereological fallacy, then he ascribes psychological predicates to parts of an animal that apply only to the (behaving) animal as a whole. This incoherence is not strictly speaking a fallacy, i.e. an invalid argument, since it is not an argument but an illicit predication. However, it leads to invalid inferences and arguments, and so can loosely be called a fallacy. However, discussions of this particular illicit predication, the mereological fallacy, show that it is often misunderstood. Many (...) misunderstandings concern the use of this illicit predication in the course of discussions of understanding the mind/body problem. Our aim here is to provide an accessible overview through discussing common misconceptions of the fallacy. We also discuss how conceptual investigations of the relation between living organisms and their parts fit within the framework of modern evolutionary theory, i.e. inclusivefitness theory. (shrink)
On the basis of distinctions between those properties of entities that can be defined without reference to other entities and those that (in different ways) cannot, this note argues that non-trivial forms of frequency-dependent selection of entities should be interpreted as selection occurring at a level higher than that of those entities. It points out that, except in degenerately simple cases, evolutionary game-theoretic models of selection are not models of individual selection. Similarly, models of genotypic selection such as heterosis cannot (...) be legitimately interpreted as models of genic selection. The analysis presented here supports the views that: (i) selection should be viewed as a multi-level process; (ii) upper-level selection is ubiquitous; (iii) kin selection should be viewed as a type of group selection rather than individual selection; and (iv) inclusivefitness is not an individual property. (shrink)
This book sheds new light on the problem of how the human mind evolved. Harry Smit argues that current studies of this problem misguidedly try to solve it by using variants of the Cartesian conception of the mind, and shows that combining the Aristotelian conception with Darwin's theory provides us with far more interesting answers. He discusses the core problem of how we can understand language evolution in terms of inclusivefitness theory, and investigates how scientific and conceptual (...) insights can be integrated into one explanatory framework, which he contrasts with the alternative Cartesian-derived framework. He then explores the differences between these explanatory frameworks with reference to co-operation and conflict at different levels of biological organization, the evolution of communicative behaviour, the human mind, language, and moral behaviour. His book will interest advanced students and scholars in a range of subjects including philosophy, biology and psychology. (shrink)
Inclusivefitness theory provides a compelling explanation for the evolution of altruism among kin. However, a completely satisfactory account of non-kin altruism is still lacking. The present study compared the level of altruism found among siblings with that found among friends and mates and sought to reconcile the findings with an evolutionary explanation for human altruism. Participants (163 males and 156 females) completed a questionnaire about help given to a sibling, friend, or mate. Overall, participants gave friends and (...) mates as much or more help than they gave siblings. However, as the cost of help increased, siblings received a progressively larger share of the help, whereas friends and mates received a progressively smaller share, despite the fact that participants were closer emotionally to friends and mates than they were to siblings. These findings help to explain the relative standing of friends and mates as recipients of altruistic aid. (shrink)