By conceptualizing Sexual Selection, Darwin showed a way to analyze intra-specific individual differences within an evolutionary perspective. Interestingly, Sexual Selection is often used to investigate the origins of sports, arts, humor, religion and other phenomena that, in several languages, are simply called “play.” Despite their manifested differences, these phenomena rely on shared psychological processes, including playfulness. Further, in such behaviors there is usually considerable individual variability, including sex differences, and positive relationship with mating success. However, Sexual Selection is rarely applied (...) in the study of play, with exception to what is concerned as infant training behavior for adult sex roles. We offer an integrated grounding of playful phenomena aligning evolutionary propositions based on sexual selection, which might stimulate further exploration of playfulness within evolutionary perspective. (shrink)

Early in June of 1867, Charles Darwin turned back the cover of his copy of the respected quarterlyNorth British Review, to find on its opening pages a lengthy essay attacking his theory of natural selection. As with the vast majority of articles in the Victorian periodicals, the review was anonymous, prompting immediate speculation in Darwin's circle as to the author's identity. It was to be about a year-and-a-half before Darwin would learn that the engineer Fleeming Jenkin had written the essay. (...) By then, Darwin had concluded that the critique was the most valuable he had ever read onThe Origin of Species. (shrink)

In this article (1) I extract from Brentano’s works (three) formal arguments against “genealogical explanations” of ethical claims. Such explanation can also be designated as “naturalism” (not his appellation); (2) I counter these arguments, by showing how genealogical explanations of even apodictic moral claims are logically possible (albeit only if certain unlikely, stringent conditions are met); (3) I show how Nietzsche’s ethics meets these stringent conditions, but evolutionary ethics does not. My more general thesis is that naturalism and intuitionism in (...) ethics need not be mutually incompatible. (shrink)

In this article (1) I extract from Brentano’s works (three) formal arguments against “genealogical explanations” of ethical claims. Such explanation can also be designated as “naturalism” (not his appellation); (2) I counter these arguments, by showing how genealogical explanations of even apodictic moral claims are logically possible (albeit only if certain unlikely, stringent conditions are met); (3) I show how Nietzsche’s ethics meets these stringent conditions, but evolutionary ethics does not. My more general thesis is that naturalism and intuitionism in (...) ethics need not be mutually incompatible. (shrink)

There is a rather striking video currently used in police training. A firearms officer is caught on video shooting an armed suspect. The officer then gives his account of what happened, and there is no suggestion that he is tying to fabricate evidence. He says that he shot the suspect once; his partner says that he fired two shots. On the video we see four shots being deliberately fired. Memory, it seems, is an unreliable witness in situations of stress.

For humans and many other animals, gender is a fact of life. Most individuals are born either male or female and their sex will have an enormous influence on their behaviour, physiology and life history. In this review, I consider the effect gender has on lifespan. In particular, I discuss the role played by behaviour, immunity and oxidative damage in determining sex‐dependent differences in longevity. I consider existing explanations for the effect of gender on lifespan and how these explanations fit (...) together. Finally, I expand on the recent suggestion of a key role for the insulin/IGF‐1 signalling pathway in regulating sex‐dependent differences in lifespan(1) and I highlight a number of areas for future investigation. BioEssays 29:795–802, 2007. © 2007 Wiley Periodicals, Inc. (shrink)

I admire Wilson & Sober's (W & S's) aim, to alert social scientists that group selection has risen from the ashqs, and to explicate its relevance to the behavioral sciences. Group selection has beenwidely misunderstood; furthermore, both authors have been instrumental in illuminating conceptual problems surrounding higher-level selection. Still, I find that this target article muddies the waters, primarily through its shifting and confused definition of a "vehicle" of selection. The fundamental problem is an ambiguity in the definition of "adaptation." (...) On the one hand, any evolutionary change that results from a selection process could be called an adaptation, by definition; I call this the "weak" view of adaptation. A "strong" view of adaptation, on the other hand, includes some notion of design - the evolution of a specific complex trait understood, in an engineering sense, to provide a mechanism favoring its owner's success in contributing to the evolutionary lineage. (shrink)

Sex differences in mortality rates stem from genetic, physiological, behavioral, and social causes that are best understood when integrated in an evolutionary life history framework. This paper investigates the Male-to-Female Mortality Ratio (M:F MR) from external and internal causes and across contexts to illustrate how sex differences shaped by sexual selection interact with the environment to yield a pattern with some consistency, but also with expected variations due to socioeconomic and other factors.

The evolution of cooperative breeding is complex, and particularly so in humans because many other life history traits likely evolved at the same time. While cooperative childrearing is often presumed ancient, the transition from maternal self-reliance to dependence on allocare leaves no known empirical record. In this paper, an exploratory model is developed that incorporates probable evolutionary changes in birth intervals, juvenile dependence, and dispersal age to predict under what life history conditions mothers are unable to raise children without adult (...) cooperation. The model’s outcome variable (net balance) integrates dependent children’s production and consumption as a function of varying life history parameters to estimate the investment mothers or others have to spend subsidizing children. Results suggest that maternal-juvenile cooperation can support the early transition toward a reduction in birth intervals, a longer period of juvenile dependence, and having overlapping young. The need for adult cooperation is most evident when birth intervals are short and age at net production is late. Findings suggest that the needs of juveniles would not have been an early selective force for adult cooperation. Rather, an age-graded division of labor and the mutual benefits of maternal-juvenile cooperation could be an important, but overlooked step in the evolution of cooperative breeding. (shrink)

Geary's model is a worthy effort, but ambiguous on important issues. It ignores differential resource allocation, although this follows directly from sexual selection via differential parental investment. Dimorphism in primary traits is arbitrarily attributed to sexual selection via intramale competition, rather than direct evolutionary pressures. Dubious predictions are made about the consequences of raising mathematics achievement.

Among the extra-physical aspects of team sports, the ways in which players talk to each other are among the more colorful but understudied dimensions of competition. To contribute an empirical basis for examining the nature of “trash talk,” we present the results of a study of 291 varsity athletes who compete in the top division among US universities. Based on a preliminary review of trash-talk topics among student-athletes, we asked participants to indicate the frequency with which they have communicated or (...) heard others talk about opposing players’ athleticism, playing ability, physical appearance, boyfriends, girlfriends, sexual behavior, parents, and home institution during competitions. Our three main findings are: Trash-talking is most commonly about the proximately important topic of playing ability while ultimately relevant topics such as physical appearance also appear to be common; Men appear to trash-talk significantly more than women, and consistently across topics; and contact sports such as football, hockey, lacrosse, and wrestling are associated with trash talk significantly more than other sports. We also examined whether the anonymity provided by face-masked helmets in “combat sports” was associated with more trash talk than contact sports played without a helmet and found no consistent association with face masks. Our findings highlight the ways in which competitors in physical sporting contests attempt to use language—often in ways that focus on players’ kin or reproductive interests—in pursuit of victory while establishing a baseline for future research into trash-talking. (shrink)

Geary's emphasis on hunting ignores the possible importance of other human activities, such as scavenging and gathering, in the evolution of spatial abilities. In addition, there is little evidence that links spatial abilities and math skills. Furthermore, such links have little practical importance given the small size of most differences and girls' superior performance in mathematics classrooms.

Group selection may be defined either broadly or narrowly. Narrowly defined group selection may involve either selection for altruism or group selection between alternative evolutionarily stable states. The last variety of group selection is likely to have been particularly important in human evolution.

The theory of sexual selection suggests several possible explanations for the development of standards of physical attractiveness in humans. Asymmetry and departures from average proportions may be markers of the breakdown of developmental stability. Supernormal traits may present age- and sex-typical features in exaggerated form. Evidence from social psychology suggests that both average proportions and (in females) “neotenous” facial traits are indeed more attractive. Using facial photographs from three populations (United States, Brazil, Paraguayan Indians), rated by members of the same (...) three populations, plus Russians and Venezuelan Indians, we show that age, average features, and (in females) feminine/neotenous features all play a role in facial attractiveness. (shrink)

To the extent that Geary's theory concerning biologically primary and secondary behaviors depends on factor analytic methods and findings, it is woefully weak. Factors have been mistakenly called primary mental abilities, but the adjective “primary” represents reification of a mathematical dimension defined by correlations. Fleshing out a factor beyond its mathematical properties requires much additional quantitative experimental and correlational research that goes far beyond mere factoring.

The life of George Price (1922-1975), the eccentric polymath genius and father of the Price equation, is used as a prism and counterpoint through which to consider an age-old evolutionary conundrum: the origins of altruism. This biographical project, and biography and history more generally, are considered in terms of the possibility of using form to convey content in particular ways. Closer to an art form than a science, this approach to scholarship presents both a unique challenge and promise.

The jargon of evolutionary psychology has recently migrated from a few minor American universities into the academic mainstream and thence into Sunday supplements and dinner party conversations. It has even formed the backdrop to at least one award-winning novel (McEwan, 1997). Evolutionary psychology and other similar ‘biological’ explanations of human conduct pervade the Zeitgeist and, as Kenan Malik has persuasively argued, they tap into a prevailing mood of cultural pessimism. Evolutionary psychology, it seems, speaks to our desire to see the (...) worst in ourselves (Malik, 2002). (shrink)

Although Geary's partitioning of mathematical abilities into those that are biologically primary and secondary is an advance over most sociobiological theories of cognitive sex differences, it remains untestable and ignores the spatial nature of women's traditional work. An alternative model based on underlying cognitive processes offers other advantages.

A number of philosophers and ‘evolutionary psychologists’ have argued that attacks on adaptationism in contemporary biology are misguided. These thinkers identify anti-adaptationism with advocacy of non-adaptive modes of explanation. They overlook the influence of anti-adaptationism in the development of more rigorous forms of adaptive explanation. Many biologists who reject adaptationism do not reject Darwinism. Instead, they have pioneered the contemporary historical turn in the study of adaptation. One real issue which remains unresolved amongst these methodological advances is the nature of (...) ‘phylogenetic inertia’. To what extent is an adaptive explanation needed for the persistence of a trait as well as its origin? (shrink)

Challenged by Lord Kelvin's claims that earth and sun were too young to give evolution sufficient time to do its work, especially in the human case, where care for the weak blunts the edge of natural selection, Darwin leaned on Lamarckian thoughts to accelerate the process. The mental and moral traits crowning human distinctiveness, he urged, arose through sexual selection. But promiscuity, infanticide, early betrothals, and female drudgery undermined these effects in “savage races.” In the inevitable decline and ultimate extinction (...) of the “melanin races” Darwin believed he could observe human evolution underway before his eyes. (shrink)

This essay addresses recent claims about the compatibility of the sociobiological theory of reciprocal altruism with standard Western formulations of the Golden Rule. Derek Parfit claims that the theory of reciprocal altruism teaches us to be “reciprocal altruists,” who benefit only those people from whom we can reasonably expect benefits in the future. The Golden Rule, on the other hand, teaches us to benefit anyone regardless of their intention or ability to return the favor, or as Parfit puts it, the (...) Golden Rule teaches us to be “suckers.” I argue that this distinction is founded on a misconception of the nature of the theory of reciprocal altruism, which is sociobiological as opposed to moral, and that this distinction accordingly confuses is with ought. Sociobiological theories may explain underlying psychological motivations in individuals (and perhaps even in populations), but these theories do not prescribe any sort of moral behavior. Furthermore, the theory of reciprocal altruism does not imply mental states of which agents are aware. The unconscious motivations assumed by this theory are in fact compatible with certain formulations of the Golden Rule; I will accordingly argue for the view that certain words with moral content related to the Golden Rule—such as “altruism” and “selfishness”—exist only insofar as they are social tools, which can further the self-interests of an individual in any group. (shrink)

In Darwinian terminology, “sexual selection” refers to purely reproductive competition and is conceptually distinct from natural selection as it affects reproduction generally. As natural selection may favor the evolution of sexual dimorphism by virtue of the division of labor between males and females, this possibility needs to be taken very seriously.

In this paper, I ask feminist philosophers and science studies scholars to consider the goals of developing critical analyses of evolutionary psychology. These goals can include development of scholarship in feminist philosophy and science studies, mediation of the uptake of evolutionary psychology by other academic and lay communities, and improvement of the practices and products of evolutionary psychology itself. I evaluate ways that some practices of feminist philosophy and science studies facilitate or hinder meeting these goals, and consider the merits (...) of critical engagement with some of the scientists themselves. Finally, I describe a community of feminist evolutionary psychologists with whom it might be both fruitful and interesting to engage, and identify ways that these interactions may benefit the science and the study of the science. (shrink)

In Section 1, I introduce three views that explain human cognitive development from different standpoints: Marcus’s neo-nativism, standard neuroconstructivism, and neo-neuroconstructivism. In Section 2, I assess Marcus’s attempt to reconcile nativism with developmental flexibility. In Section 3, I argue that in structurally reconfiguring nativism, Marcus ends up transforming it into an unrecognizable form, and I claim that his view could be accommodated within the more general framework provided by standard neuroconstructivism. In Section 4, I focus on recent empirical findings in (...) neuropsychology and cultural/social neuroscience, and propose a friendly revision to standard neuroconstructivism, thus developing the neo-neuroconstructivist view. I conclude the article in Section 5 by analysing the implications of the results discussed in Section 4 for both neo-nativism and standard neuroconstructivism. 1 Introduction2 Marcus’s Neo-nativism3 Is Marcus’s Neo-nativism Really a Form of Nativism?4 Neo-neuroconstructivism and Dynamic Enskillment5 Conclusion. (shrink)

Although classical evolutionary theory, i.e., population genetics and the Modern Synthesis, was already implicitly ‘gene-centred’, the organism was, in practice, still generally regarded as the individual unit of which a population is composed. The gene-centred approach to evolution only reached a logical conclusion with the advent of the gene-selectionist or gene’s eye view in the 1960s and 1970s. Whereas classical evolutionary theory can only work with (genotypically represented) fitness differences between individual organisms, gene-selectionism is capable of working with fitness differences (...) among genes within the same organism and genome. Here, we explore the explanatory potential of ‘intra-organismic’ and ‘intra-genomic’ gene-selectionism, i.e., of a behavioural-ecological ‘gene’s eye view’ on genetic, genomic and organismal evolution. First, we give a general outline of the framework and how it complements the—to some extent—still ‘organism-centred’ approach of classical evolutionary theory. Secondly, we give a more in-depth assessment of its explanatory potential for biological evolution, i.e., for Darwin’s ‘common descent with modification’ or, more specifically, for ‘historical continuity or homology with modular evolutionary change’ as it has been studied by evolutionary developmental biology (evo-devo) during the last few decades. In contrast with classical evolutionary theory, evo-devo focuses on ‘within-organism’ developmental processes. Given the capacity of gene-selectionism to adopt an intra-organismal gene’s eye view, we outline the relevance of the latter model for evo-devo. Overall, we aim for the conceptual integration between the gene’s eye view on the one hand, and more organism-centred evolutionary models (both classical evolutionary theory and evo-devo) on the other. (shrink)

Although classical evolutionary theory, i.e., population genetics and the Modern Synthesis, was already implicitly ‘gene-centred’, the organism was, in practice, still generally regarded as the individual unit of which a population is composed. The gene-centred approach to evolution only reached a logical conclusion with the advent of the gene-selectionist or gene’s eye view in the 1960s and 1970s. Whereas classical evolutionary theory can only work with fitness differences between individual organisms, gene-selectionism is capable of working with fitness differences among genes (...) within the same organism and genome. Here, we explore the explanatory potential of ‘intra-organismic’ and ‘intra-genomic’ gene-selectionism, i.e., of a behavioural-ecological ‘gene’s eye view’ on genetic, genomic and organismal evolution. First, we give a general outline of the framework and how it complements the—to some extent—still ‘organism-centred’ approach of classical evolutionary theory. Secondly, we give a more in-depth assessment of its explanatory potential for biological evolution, i.e., for Darwin’s ‘common descent with modification’ or, more specifically, for ‘historical continuity or homology with modular evolutionary change’ as it has been studied by evolutionary developmental biology during the last few decades. In contrast with classical evolutionary theory, evo-devo focuses on ‘within-organism’ developmental processes. Given the capacity of gene-selectionism to adopt an intra-organismal gene’s eye view, we outline the relevance of the latter model for evo-devo. Overall, we aim for the conceptual integration between the gene’s eye view on the one hand, and more organism-centred evolutionary models on the other. (shrink)

The theory of evolution by natural selection is, perhaps, the crowning intellectual achievement of the biological sciences. There is, however, considerable debate about which entity or entities are selected and what it is that fits them for that role. This article aims to clarify what is at issue in these debates by identifying four distinct, though often confused, concerns and then identifying how the debates on what constitute the units of selection depend to a significant degree on which of these (...) four questions a thinker regards as central. (shrink)

This article gives a short presentation of reflexive imperativism, the intentionalist theory of valence I developed with Max Khan Hayward. The theory says that mental states have valence in virtue of having reflexive imperative content. More precisely, mental states have positive valence (i.e., feel good) in virtue of issuing the command "More of me!", and they have negative valence (i.e., feel bad) in virtue of issuing the command "Less of me!" The article summarises the main arguments in favour of reflexive (...) imperativism and against other intentionalist treatments of valence. (shrink)