What is Causal Specificity About, and What is it Good for in Philosophy of Biology?

The concept of causal specificity is drawing considerable attention from philosophers of biology. It became the rationale for rejecting (and occasionally, accepting) a thesis of causal parity of developmental factors. This literature assumes that attributing specificity to causal relations is at least in principle a straightforward (if not systematic) task. However, the parity debate in philosophy of biology seems to be stuck at a point where it is not the biological details that will help move forward. In this paper, I take a step back to reexamine the very idea of causal specificity and its intended role in the parity dispute in philosophy of biology. I contend that the idea of causal specificity across variations as currently discussed in the literature is irreducibly twofold in nature: it is about two independent components that are not mutually entailed. I show this to be the source of prior complications with the notion of specificity itself that ultimately affect the purposes for which it is often invoked, notably to settle the parity dispute.

Causation, Causal Selection, and Causal Parity

It is typical to refer to cancer as a “genetic” or “genomic” disease. This claim is ambiguous; one of the central goals of this chapter is to disambiguate this claim. I first distinguish different types of causal claims: claims about causal relevance, causal role, and causal specificity. As a backdrop to this discussion, I introduce what I call the “mechanistic research program” in cancer, according to which progression to cancer involves breakdowns in regulatory controls on gene expression in ways that affect cell birth and death. While this research program has been successful, it has downplayed the role of context in cancer progression, and the fact that disorderly cellular growth is affected by many pathways. I conclude by considering several philosophers’ accounts of “causal selection” and argue that ultimately the causal selection problem is not one but several different problems, requiring different, context-specific solutions.

Defining Metabolic Syndrome: Which Kind of Causality, if any, is Required?

The definition of metabolic syndrome (MetS) has been, and still is, extremely controversial. My purpose is not to give a solution to the associated debate but to argue that the controversy is at least partially due to the different ‘causal content’ of the various definitions: their theoretical validity and practical utility can be evaluated by reconstructing or making explicit the underlying causal structure. I will therefore propose to distinguish the alternative definitions according to the kinds of causal content they carry: (1) definitions grounded on associations, (2) definitions presupposing a causal model built upon statistical associations, and (3) definitions grounded on underlying mechanisms. I suggest that analysing definitions according to their causal content can be helpful in evaluating alternative definitions of some diseases. I want to show how the controversy over MetS suggests a distinction among three kinds of definitions based on how explicitly they characterise the syndrome in causal terms, and on the type of causality involved. I will call ‘type 1 definitions’ those definitions that are purely associative; ‘type 2 definitions’ the definitions based on statistical associations, plus generic medical and causal knowledge; and ‘type 3 definitions’ the definitions based on (hypotheses about) mechanisms. These kinds of definitions, although different, can be related to each other. A definition with more specific causal content may be useful in the evaluation of definitions characterised by a lower degree of causal specificity. Moreover, the identification of the type of causality involved is of help to constitute a good criterion for choosing among different definitions of a pathological entity. In section (1) I introduce the controversy about MetS, in section (2) I propose some remarks about medical definitions and their ‘causal import’, and in section (3) I suggest that the different attitudes towards the definition of MetS are relevant to evaluate their explicative power.

Genetic, epigenetic and exogenetic information in development and evolution

The idea that development is the expression of information accumulated during evolution and that heredity is the transmission of this information is surprisingly hard to cash out in strict, scientific terms. This paper seeks to do so using the sense of information introduced by Francis Crick in his sequence hypothesis and central dogma of molecular biology. It focuses on Crick's idea of precise determination. This is analysed using an information-theoretic measure of causal specificity. This allows us to reconstruct some of Crick's claims about information in transcription and translation. Crick's approach to information has natural extensions to non-coding regions of DNA, to epigenetic marks, and to the genetic or environmental upstream causes of those epigenetic marks. Epigenetic information cannot be reduced to genetic information. The existence of biological information in epigenetic and exogenetic factors is relevant to evolution as well as to development.

A Systematic Review of Mechanisms of Change in Body-Oriented Yoga in Major Depressive Disorders

Introduction Despite empirical evidence for the efficacy of body-oriented yoga as add-on treatment for major depressive disorder (MDD), the specific mechanisms by which yoga leads to therapeutic changes remain unclear. By means of a systematic review, we evaluate how the field is progressing in its empirical investigation of mechanisms of change in yoga for MDD. Methods To identify relevant studies, a systematic search was conducted. Results The search produced 441 articles, of which 5 were included, that empirically examined 2 psychological mechanisms (mindfulness, rumination) and 3 biological mechanisms (vagal control, heart rate variability [HRV], brain-derived neurotrophic factor [BDNF], cortisol). 2 studies found that decreased rumination and 1 study that increased mindfulness was associated with the effect of yoga on treatment outcome. In addition, preliminary studies suggest that alterations in cortisol, BDNF, and HRV may play a role in how yoga exerts its clinical effect. Discussion The results suggest that body-oriented yoga could work through some of the theoretically predicted mechanisms. However, there is a need for more rigorous designs that can assess greater levels of causal specificity.

The importance of being explicit

Van Lange et al. propose that climate affects violence via its effects on life history. That much is reasonable (and not novel), but their theory lacks causal specificity. Their foundational claim of an association between heat and violence is not well documented, and several findings that the authors themselves cite seem inconsistent with their model, rather than supportive.