A number of debates in philosophy of biology and psychology, as well as in their respective sciences, hinge on particular views about the relationship between genotypes and phenotypes. One such view is that the genotype-phenotype relationship is relatively straightforward, in the sense that a genome contains the ?genes for? the various traits that an organism exhibits. This leads to the assumption that if a particular set of traits is posited to be present in an organism, there must be a corresponding (...) number of genes in that organism's genome to account for those traits. This assumption underlies what can be called the ?counting argument,? in which empirical estimates of the number of genes in a genome are used to support or refute particular hypotheses in philosophical debates about biology and psychology. In this paper, we assess the counting argument as it is used in discussions of the alleged massive modularity of the brain, and conclude that this argument cannot be upheld in light of recent philosophical work on gene concepts and empirical work on genome complexity. In doing so, we illustrate that there are those on both sides of the debate about massive modularity who rely on an incorrect view of gene concepts and the nature of the genotype-phenotype relationship. (shrink)

David Buller and Valerie Hardcastle have argued that various discoveries about the genetics and nature of brain development show that most ?central? psychological mechanisms cannot be adaptations because the nature of the contribution from the environment on which they are based shows they are not heritable. Some philosophers and scientists have argued that a strong role for the environment is compatible with high heritability as long as the environment is highly stable down lineages. In this paper I support this view (...) by arguing that the discoveries Buller and Hardcastle refer to either do not show as strong a role for the environment as they suggest, or these discoveries show that the brain's developmental process depends in many cases on input from the environment that is highly stable across generations. (shrink)

The value of rational choice theory for the social sciences has long been contested. It is argued here that, in the debate over its role, it is necessary to distinguish between claims that people maximise manifest payoffs, and claims that people maximise their utility. The former version has been falsified. The latter is unfalsifiable, because utility cannot be observed. In principle, utility maximisation can be adapted to fit any form of behaviour, including the behaviour of non-human organisms. Allegedly 'inconsistent' behaviour (...) is also impossible to establish without qualification. This utility-maximising version of rational choice theory has the character of a universal 'explanation' that can be made to 'fit' any set of events. This is a sign of weakness rather than strength. In its excessive quest for generality, utility-maximising rational choice theory fails to focus on the historically and geographically specific features of socio-economic systems. As long as such theory is confined to ahistorical generalities, then it will remain highly limited in dealing with the real world. Instead we have to consider the real social and psychological determinants of human behaviour. (shrink)

Evolutionary psychology as commonly presented is committed to the view that our cognitive architecture consists of a set of genetically pre-specified, domain specific, computational modules that are adaptations to the environment of our Pleistocene ancestors. These commitments yield a picture in which the underlying computational design of the human mind is genetically transmitted while cultural variation results from differential experiential inputs being processed through this common architecture. This view has been criticized from a developmental point of view. This paper develops (...) some of those criticisms specifically as they relate to the plasticity of neural structures and their responsiveness to social interactions. In best case scenarios the confirmation of adaptive explanations involves identifying the specific causal mechanisms of selection. This is illustrated in examples from ecological genetics. This is not possible in the case of evolutionary psychology. Instead claims that certain computational modules evolved as adaptations in the ancestral environment are supported by their cross-cultural occurrence in modern populations. However, evidence suggests that behavior itself, and cultural practices, are factors that influence the development of neural structures and the cognitive processes they instantiate. So while genes are playing a role in the development of the brain, they do not really encode its neural architecture. When selection favors one set of neural characteristics over alternatives, the genes that played a role in the development of those structures are passed on. But this does not guarantee replication of the structures themselves. What is being selected? Not genes, but organisms with certain neurological and behavioral tendencies in particular environments. Variation in the genetic determinants of neurological structure is not a necessary condition for natural selection to act on behavior. The necessary condition, as Darwin originally put the point, is that traits are heritable. Certainly heritability implies some genetic transmission between generations. But heritability of neural structure requires more than a genetic determinant because neural structures are so plastic. Some regulation of the experiential environment in which those genes act is also necessary. This suggests that an adequate account of the evolution of behavior requires a multi-level approach that recognizes that gene action and social behavior are related by a kind of causal reciprocity. Such an account would be quite different than the evolutionary psychologists’ model of culture being layered over the top of an underlying cognitive computer that is genetically propagated. (shrink)