We often hear how scientists have discovered that a certain human trait – or a trait of another type of organism – is innate, genetic, heritable, inherited, naturally selected etc. All these claims have something in common: they all declare a trait to have significant organism internal (for instance genetic) causes that are present in the organism at its birth. I call claims like these “nativist claims”. Nativist claims are important. They shape our overall understanding of what we are, what (...) we can do and what is good for us. They also impact our practical decision making. For instance, we know that certain types of genes increase the risk of certain diseases, and increasingly this has an effect on healthcare practices. Many people believe that in the matter of children’s education we should consider the fact that many cognitive abilities are highly heritable. Associations between genetics and aggressive behavior have been taken to be alleviating circumstances in criminal sentencing. It is therefore important to correctly understand the content and implications of nativist claims. In this doctoral thesis I analyze, by philosophical means, the content of different kinds of nativist claim. What does it mean that some psychological tendency is innate? What does it mean that intelligence is 50% heritable? How (if at all) do genes come to carry information about the traits of an organism – they are nothing like the information carriers familiar to us, such as newspapers, e-mails, secret codes, and audio files. This thesis emphasizes two things. Firstly, I demonstrate, that in different scientific contexts these words ('innate', 'genetically caused' etc.) can mean very different things. Therefore, the implications of a given nativist claim in one scientific context can be remarkably different from another nativist claim’s implications in some other scientific context. Secondly, I explain how the development of innate, heritable and genetically caused traits can be determined in different and often unexpected ways by our environment and experiences. I demonstrate that the content of a concept that is considered innate by cognitive scientists can be determined by what the organism that possesses the concept has experienced. I also show that even a trait which is 100% heritable can at the same time be a socially constructed trait. (shrink)

This paper explores the interpretation and use of polygenic risk scores (PRSs). We argue that PRSs generally do not directly embody causal information. Nonetheless, they can assist us in tracking other causal relationships concerning genetic effects. Although their purely predictive/correlational use is important, it is this tracking feature that contributes to their potential usefulness in other applications, such as genetic dissection, and their use as controls, which allow us, indirectly, to "see" more clearly the role of environmental variables.

It is now well-appreciated by philosophers that contemporary large-scale ‘-omics’ studies in biology stand in non-trivial relationships to more orthodox hypothesis-driven approaches. These relationships have been clarified by Ratti (2015); however, there remains much more to be said regarding how an important field of genomics cited in that work—‘genome-wide association studies’ (GWAS)—fits into this framework. In the present article, we propose a revision to Ratti’s framework more suited to studies such as GWAS. In the process of doing so, we introduce (...) to the philosophical literature novel exploratory experiments in (phospho)proteomics, and demonstrate how these experiments interplay with the above considerations. (shrink)

Research in pharmacogenomics and precision medicine has recently introduced the concept of Polygenic Scores (PGSs), namely, indexes that aggregate the effects that many genetic variants are predicted to have on individual disease risk. The popularity of PGSs is increasing rapidly, but surprisingly little attention has been paid to the idealisations they make about phenotypic development. Indeed, PGSs rely on quantitative genetics models and methods, which involve considerable theoretical assumptions that have been questioned on various grounds. This comes with epistemological and (...) ethical concerns about the use of PGSs in clinical decision-making. In this paper, I investigate to what extent idealisations in genetics models can impact the data gathering and clinical interpretation of genomics findings, particularly the calculation and predictive accuracy of PGSs. Although idealisations are considered ineliminable components of scientific models, they may be legitimate or not depending on the epistemic aims of a model. I thus analyse how various idealisations have been introduced in classical models and progressively readapted throughout the history of genetic theorising. Notably, this process involved important changes in the epistemic purpose of such idealisations, which raises the question of whether they are legitimate in the context of contemporary genomics. (shrink)

Behavior genetics is a controversial science. For decades, scholars have sought to understand the role of heredity in human behavior and life-course outcomes. Recently, technological advances and the rapid expansion of genomic databases have facilitated the discovery of genes associated with human phenotypes such as educational attainment and substance use disorders. To maximize the potential of this flourishing science, and to minimize potential harms, careful analysis of what it would mean for genes to be causes of human behavior is needed. (...) In this paper, we advance a framework for identifying instances of genetic causes, interpreting those causal relationships, and applying them to advance causal knowledge more generally in the social sciences. Central to thinking about genes as causes is counterfactual reasoning, the cornerstone of causal thinking in statistics, medicine, and philosophy. We argue that within-family genetic effects represent the product of a counterfactual comparison in the same way as average treatment effects (ATEs) from randomized controlled trials (RCTs). Both ATEs from RCTs and within-family genetic effects are shallow causes: They operate within intricate causal systems (non-unitary), produce heterogeneous effects across individuals (non-uniform), and are not mechanistically informative (non-explanatory). Despite these limitations, shallow causal knowledge can be used to improve understanding of the etiology of human behavior and to explore sources of heterogeneity and fade-out in treatment effects. (shrink)

Madole & Harden plead for better integration of causal knowledge of different depths to understand complex human traits. Classically, local causes – a particular type of shallow causes – are considered less useful than more generalisable causes, giving a false impression that the latter causes are more useful and desirable. Using a simple example, I show that sometimes the contrary is true.

Lucas Matthews and I substantially revised my SEP entry on Heritability. This version includes discussion of the missing heritability problem and other issues that arise from the use of Genome Wide Association Studies by Behavioral Geneticists.

Invariance is one of several dimensions of causal relationships within the interventionist account. The more invariant a relationship between two variables, the more the relationship should be considered paradigmatically causal. In this paper, I propose two formal measures to estimate invariance, illustrated by a simple example. I then discuss the notion of invariance for causal relationships between non-nominal (i.e., ordinal and quantitative) variables, for which Information theory, and hence the formalism proposed here, is not well suited. Finally, I propose how (...) invariance could be qualified for such variables. (shrink)