Some Criticism of the Contextual Approach, and a Few Proposals

Abstract

The contextual approach is a prominent framework for thinking about group selection. Here, I highlight ambiguity about what the contextual approach is. Then, I discuss problematic entailments the contextual approach has for what processes count as group selectionentailments more troublesome than typically noted. However, Sober and Wilson's version of the Price approach, which is the main alternative to the contextual approach, is problematic too: it leads to an underappreciated paradox called the vanishing selection problem and thereby generates the wrong qualitative account of whether group selection is occurring in a certain family of cases. In response, I develop an account of group selection that can deal with the counterexamples to both the contextual approach and the Price approach. I then discuss the role that contextual analysis can continue to play in the discussion of individual fitness and metapopulation evolution.

Multi-level selection and the issue of environmental homogeneity

“…The Pricean and the contextualist interpretations are usually seen as two competing ways of understanding MLS1 group selection (Okasha 2004a(Okasha , b, 2005(Okasha , 2006(Okasha , 2011Kerr 2009;Sober 2011Sober , 2015Goodnight 2015;Earnshaw 2015;McLoone 2015). In what follows, I will argue that it is more accurate and more enlightening to regard them as two diverging positions with respect to EHR in MLS1 scenarios.…”

“…This equation also holds for cases of single-level selection with accidental distribution of types across environments of different quality, like Brandon's Drift-Case from Section 3 (of course, in such cases the subscript j will refer to the different environments of the case -and not to groups -, and j Z will thus denote the average value of the phenotypic character in the j th environment). 22 Sober (2015, 839) -followed by McLoone (2015) -suggests that the wider version of the objection "may beg the question", but he does not bring further arguments in support of this claim. In Jeler (2016), I contested Sober's point, but on grounds that become questionable once we bring EHR into the discussion.…”

“…Okasha 2006;Earnshaw 2015;McLoone 2015;Sober 2015 2 ). I will argue below that this presentation of the two interpretations is incomplete.…”

Identifying causes of social evolution: The Price approach, contextual analysis, and multilevel selection

“…Contextual analysis (Heisler and Damuth 1987; Okasha, 2006; note that here and the following we refer by ‘contextual analysis’ to the standard regression on the untransformed variables x and X , as is customary in discussions on the issues reported here) takes effects of the group trait in Equation (1) as indicating group selection. Strictly speaking, c 2 ≠ 0 in Equation (1) implies the potential of the trait to undergo group selection conditional on the existence of group-trait variation between groups (Wolf et al, 1999; see McLoone (2015) for a discussion of this difference). We regard group effects on fitness as more fundamental than a concept of group selection itself as the former do not depend on properties of a population but reflect causal processes that increase or decrease reproductive success of an individual situated in a group context vis-à-vis a specific selection regime that in turn determines individual fitness.…”

“…Two methods for carrying out a quantitative decomposition of individual fitness into an individual component and a group component have received particular attention in the literature (Heisler and Damuth, 1987; Goodnight, Schwartz, and Stevens, 1992; Frank, 1998; Okasha, 2006; Sober 2011, McLoone, 2015): the multilevel Price equation and contextual analysis which, following Okasha, we refer to as the ‘Price approach’ and the ‘contextual approach’, resp. However, the partitions of individual fitness given by the two methods are different in general.…”