In this article, we discuss epistemological limitations relating to the use of ethnoracial categories in biomedical research as devised by the Office of Management and Budget’s institutional guidelines. We argue that the obligation to use ethnoracial categories in genomics research should be abandoned. First, we outline how conceptual imprecision in the definition of ethnoracial categories can generate epistemic uncertainty in medical research and practice. Second, we focus on the use of ethnoracial categories in medical genetics, particularly genomics-based precision medicine, where (...) ethnoracial identity is understood as a proxy for medically relevant differences among individuals. Notably, extensive criticisms have been made already against the genetic interpretation of races, but, nonetheless, the concept of race remains a key element of contemporary genomics. This motivates us to explore possible reasons why such criticisms may have been ineffective in redirecting attention to other (non-race-based) ways of controlling for human variability. We contend that popular arguments against the idea that human races have a genetic basis, though convincing in many respects, are not sufficient to exclude the pragmatic use of race and ethnicity as proxies for genetic variability related to complex phenotypes. Finally, we provide two further arguments to support the idea that ethnoracial categories are unlikely to provide meaningful insights into medical genetics, which implies that even the interpretation of race as a useful tool to stratify disease risk is unwarranted. (shrink)

Recent trends in psychiatry involve a transition from categorical to dimensional frameworks, in which the boundary between health and pathology is understood as a difference in degree rather than as a difference in kind. A major tenet of dimensional approaches is that no qualitative distinction can be made between health and pathology. As a consequence, these approaches tend to characterize such a threshold as pragmatic or conventional in nature. However, dimensional approaches to psychopathology raise several epistemological and ontological issues. First, (...) we review major sources of evidence usually recruited in support of the dimensional trend (focusing on clinical observation and biological data), and we show that these are connected to different conceptualizations of how dimensional traits extend across health and pathology. Second, we criticize two unquestioned assumptions that stand at the core of the dimensional trend: a) that there is continuity from health to pathology at the symptomatic level; b) that such continuity reflects an underlying continuity in the genetic liability for pathological conditions. Third, we argue against the idea of a conventional threshold by showing that such a view implies a linear relationship between the genotype and the phenotype. Fourth, drawing on epigenetics and developmental biology, we offer a characterization of mental disorders as stable and dynamic constellations of multi-level variables that differ qualitatively from ‘healthy states’. We conclude by showing that our account has several theoretical advantages over both categorical and dimensional approaches. Notably, it provides crucial insights into psychological development over time and individual differences, with major implications in terms of intervention and clinical decision-making. (shrink)

Recurrent, unvarying, and seemingly purposeless patterns of action and cognition are part of normal development, but also feature prominently in several neuropsychiatric conditions. Repetitive stereotyped behaviors can be viewed as exaggerated forms of learned habits and frequently correlate with alterations in motor, limbic, and associative basal ganglia circuits. However, it is still unclear how altered basal ganglia feedback signals actually relate to the phenomenological variability of RSBs. Why do behaviorally overlapping phenomena sometimes require different treatment approaches−for example, sensory shielding strategies (...) versus exposure therapy for autism and obsessive-compulsive disorder, respectively? Certain clues may be found in recent models of basal ganglia function that extend well beyond action selection and motivational control, and have implications for sensorimotor integration, prediction, learning under uncertainty, as well as aesthetic learning. In this paper, we systematically compare three exemplary conditions with basal ganglia involvement, obsessive-compulsive disorder, Parkinson’s disease, and autism spectrum conditions, to gain a new understanding of RSBs. We integrate clinical observations and neuroanatomical and neurophysiological alterations with accounts employing the predictive processing framework. Based on this review, we suggest that basal ganglia feedback plays a central role in preconditioning cortical networks to anticipate self-generated, movement-related perception. In this way, basal ganglia feedback appears ideally situated to adjust the salience of sensory signals through precision weighting of new sensory information, relative to the precision of predictions based on prior generated models. Accordingly, behavioral policies may preferentially rely on new data versus existing knowledge, in a spectrum spanning between novelty and stability. RSBs may then represent compensatory or reactive responses, respectively, at the opposite ends of this spectrum. This view places an important role of aesthetic learning on basal ganglia feedback, may account for observed changes in creativity and aesthetic experience in basal ganglia disorders, is empirically testable, and may inform creative art therapies in conditions characterized by stereotyped behaviors. (shrink)

Realists about mental disorder have been hasty about dismissing social explanations of how mental disorder is constituted. However, many social ontologies are realist ontologies. In order to create a meaningful distinction between realism and social metaphysics about mental disorder, I propose that realism about mental disorder is best understood as Individual Trait Realism (ITR) about them. For ITR, mental disorders exist in virtue of traits. I defend the view that ITR is compatible with social metaphysics, arguing that, in asking whether (...) constituents in the social sphere figure the metaphysics of psychopathology, we are asking questions on three different strata of explanation: the strata of demarcation, instantiation, and individual traits. Distinguishing between these strata allows for nuanced realism that need not reject the social constitution of mental disorder. (shrink)

The aim of this virtual special issue is to bring together philosophical and historical perspectives to address long-standing issues in the interpretation, utility, and impacts of quantitative genetics methods and findings. Methodological approaches and the underlying scientific understanding of genetics and heredity have transformed since the field's inception. These advances have brought with them new philosophical issues regarding the interpretation and understanding of quantitative genetic results. The contributions in this issue demonstrate that there is still work to be done integrating (...) old and new methodological and conceptual frameworks. In some cases, new results are interpreted using assumptions based on old concepts and methodologies that need to be explicitly recognised and updated. In other cases, new philosophical tools can be employed to synthesise historical quantitative genetics work with modern methodologies and findings. This introductory article surveys three general themes that have dominated philosophical discussion of quantitative genetics throughout history: (1) how methodologies have changed and transformed our knowledge and interpretations; (2) whether or not quantitative genetics can offer explanations relating to causation and prediction; and (3) the importance of defining the phenotypes under study. We situate the contributions in this virtual special issue within a historical framework addressing these three themes. (shrink)