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)

I defend the claim that it is possible for thoughts to be context-sensitive. Assuming that a thought is a sentence of Mentalese and content is a function from indices to truth-values, then a thought, T, is context-sensitive IFF at least one of the following three conditions are met: T exhibits character-underdeterminacy, where T is character underdetermined iff a component of T makes an explicit reference to the context to establish content. T exhibits type-underdeterminacy, where T is type underdetermined iff there (...) are tokens of T that have distinct truth-values. T is token-underdetermined, where T is token underdetermined iff for some possible states of affairs its truth-value is indeterminate. Additionally, there must be a mechanism by which the content of T can be determined by appeal to the context. Otherwise T is not sensitive to the context. The most significant objection to the possibility of context-sensitive thoughts comes from a regress argument. The concern is that any process of removing context-sensitivity from a thought will token an additional thought. If that further thought is context-sensitive, then another thought will have to be tokened. This process will only terminate when a non-context-sensitive thought is arrived at. Yet this seems to show that context-sensitivity in thought, if possible, can only be a contingent, detachable feature of thoughts. To counter this argument, I will present three versions of context-sensitive thought, mirroring each of -. These views make use of a range of relationships between thoughts and their contents or extensions that are affected by the context, but I will argue they do not require the generation of an additional thought. This provides a range of views on which thoughts can be treated as essentially context-sensitive. (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)

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)