Tomi Kokkonen Evolving in Groups Individualism and Holism in Evolutionary Explanation of Human Social Behaviour DOCTORAL DISSERTATION to be presented for public discussion with the permission of the Faculty of Arts of the University of Helsinki, in lecture room 107, Athena (Siltavuorenpenger 3 A), on the 10th of September 2021 at 13 o’clock. Filosofisia tutkimuksia Helsingin yliopistosta Filosofiska Studier från Helsingfors universitet Philosophical Studies from the University of Helsinki Publishers: Theoretical Philosophy Philosophy (Swedish) Social and Moral Philosophy P.O. Box 24 (Unioninkatu 40 A) 00014 University of Helsinki Finland Editors: Samuli Reijula Michiru Nagatsu Thomas Wallgren ISBN 978-951-51-7460-4 (paperback) ISBN 978-951-51-7461-1 (PDF) ISSN 1458-8331 (series) Unigrafia, Helsinki 2021 Abstract The main topic of this dissertation is to clarify the relationship be- tween groups and individuals in the evolutionary explanation of hu- man social behaviour. To the extent that we can understand human social behavioural traits as adaptations, are they adaptations of indi- viduals (explanatory individualism) or groups (explanatory holism)? I will distinguish three different causal dimensions in an evolutionary explanation: proximate, developmental, and evolutionary proper. An evolutionary explanation makes (implicit) assumptions about how the behaviour is produced (the proximate dimension), and how it is re- produced (the developmental dimension). Both can involve either in- dividual causal factors only or include supra-individual social factors. The main issue in the evolutionary dimension is whether group selec- tion is an important factor in evolution. The group selection contro- versy is not, however, only about the nature of selection in the hierar- chical biological organization, but also about the two other dimen- sions, as I will argue. The first topic that I discuss is what evolutionary explanation of a behavioural trait is. I will develop an evolutionary functionalist ac- count of how to individuate a behavioural trait, and I will discuss adaptationism in this context. I will show that there are three distinct defensible ideas of what an evolutionary function of a trait is, all of which are relevant. I will also distinguish between psychological, agentive, and behavioural traits in the human context, arguing that our usual way of classifying behaviour into traits is biased by folk psy- chology. After this, I will demonstrate how behavioural traits may be interactive traits that emerge in interaction and are not reducible to individual traits. This entails a non-individualist approach to adapta- tions even without group selection. As for the developmental dimen- sion, I will discuss culture and innateness within the Extended Syn- thesis interpretation of evolution. I will discuss the complexities in un- derstanding the roles of culture in evolution, and how exactly culture iii contributes to holism. My main interest in this context is, however, innateness and nativist evolutionary psychology. I will develop a new definition for innateness and defend nativism, understood in this sense, as a plausible methodological choice, while at the same time I will highlight reasons for holistic alternatives of evolutionary psychol- ogy. Finally, I will discuss the group selection controversy. I will clar- ify some of the confusions in the debate using my work in the previous chapters about the other dimensions and their relevance to selection. In particular, I will clarify the difference between kin selection and group selection, and the controversy over group adaptations. Key words: evolutionary explanation, social evolution, multilevel se- lection, group selection, culture in evolution, innateness, altruism, evolutionary psychology, evolutionary anthropology, folk psychol- ogy, mechanistic explanation iv Table of Contents Acknowledgments ................................................................................... ix 1. Introduction.......................................................................................... 1 1.1. Levels and Dimensions ......................................................................... 3 1.1.1. The Concepts of Level and Explanatory Dimensions ............. 4 1.1.2. Individualism and Holism in Three Dimensions .................... 6 1.2. On the Evolution of Human Social Behaviour ............................... 13 1.2.1. Evolutionary Explanations in Human Context ..................... 15 1.2.2. Evolution as an Integrative Perspective ................................. 21 1.2.3. Evolving in Groups.................................................................... 24 1.3. Individualism and Holism in the Evolutionary Social Science ...... 27 1.3.1. Individualism, Interactionism, and Collectivism .................. 27 1.3.2. An Overview of the Dissertation ............................................. 32 2. Explanation in Biology ..................................................................... 38 2.1. Causal Explanation .............................................................................. 38 2.1.1. The Aims of the Theory of Explanation .................................. 39 2.1.2. The Contrastive-Counterfactual Theory of Explanation ...... 43 2.1.3. Causes in Explanation ............................................................... 48 2.1.4. Invariance in Explanation ......................................................... 55 2.2. Biological Mechanisms........................................................................ 58 2.2.1. Mechanisms in Explanation ..................................................... 58 2.2.2. Natural Selection as a Mechanism ........................................... 69 3. Evolutionary Explanations of Behaviour ...................................... 77 3.1. Adaptationism and Its Criticism ....................................................... 79 3.1.1. Kinds of Adaptation Explanations .......................................... 80 3.1.2. The Problems of Adaptationism .............................................. 83 3.1.3. Adaptationism as an Explanatory Perspective ...................... 88 3.1.4. Adaptationism as a Methodological Tool............................... 94 v 3.2. Evolutionary Functionalism............................................................... 97 3.2.1. Adaptivity and the “Consensus without Unity” ................... 97 3.2.2. Adaptive Functionality and a Taxonomy of Functions ...... 105 3.2.3. A Case for Non-historical Explanatory Adaptationism ..... 111 3.2.4. The Kinds of Evolutionary Functionalism ........................... 119 3.3. Tinbergen’s Questions with Mechanistic Answers ..................... 128 3.1.1. Causation .................................................................................. 130 3.1.2. Ontogeny ................................................................................... 134 3.1.3. Evolution and Survival Value ................................................ 138 3.1.4. Interdimensional Connections ............................................... 140 4. Evolutionary Human Social Sciences .......................................... 149 4.1. Sociobiology, Broad and Narrow .................................................... 150 4.1.1. The New Synthesis .................................................................. 151 4.1.2. Kin Selection ............................................................................ 154 4.1.3. The Evolutionary Game Theory ............................................ 156 4.1.4. Group Selection ........................................................................ 158 4.1.5. Biological Markets ................................................................... 159 4.1.6. The Shortcomings of Sociobiology ........................................ 161 4.2. Evolutionary Psychology ................................................................. 163 4.2.1. Nativist Evolutionary Psychology ......................................... 166 4.2.2. Individualism and Holism in Evolutionary Psychology .... 172 4.3. Evolutionary Anthropology............................................................. 175 4.3.1. Human Behavioural Ecology ................................................. 177 4.3.2. Cultural Evolution ................................................................... 178 4.3.3. Genes and Culture in Interaction........................................... 181 4.3.4. Schools in Comparison ............................................................ 184 5. On Human Behaviour and Its Causes ......................................... 187 5.1. Preliminary Issues .............................................................................. 189 5.1.1. Evolutionary Requirements for Interactive Traits ............... 190 5.1.2. Human Behavioural Traits and the Problems with Folk Psychology ....................................................................... 192 5.1.3. Non-folksy Alternatives .......................................................... 200 vi 5.2. The Intolerable Ambiguity of Folk Psychology............................ 204 5.2.1. The Foundational Tension in the Philosophy of Folk Psychology ..... 206 5.2.2. Psychology of Folk Psychology ............................................. 210 5.2.3. The Evolution of Folk Psychology ......................................... 215 5.2.4. In Search for Clarity (by Making Things More Complex) .... 223 5.3. On Action Explanations ...................................................................