Darwinism and the Theory of Rational Choice project

About the project

The overall aim of the research project is to explore the connections between Darwinian evolutionary theory and the theory of rationality, from an overarching philosophical perspective. The starting point of the project is the existence of deep and interesting connections, both conceptual and formal, between evolutionary theory and rational choice theory. At root, these connections arise because a notion of optimization, or maximization, is central to both bodies of theory.

Evolutionary biologists typically assume that because of natural selection, animals will behave as if they are trying to maximise their Darwinian fitness (for some appropriate measure of fitness). This is the guiding assumption in much work on animal behaviour.

Rational choice theorists typically assume that humans will behave as if they are trying to maximise a utility function. This is the guiding assumption in much work in social science. Thus there is a close parallel between the notion of fitness in evolutionary theory and the notion of utility in the theory of rationality. This parallel has been noted before, by workers in a number of fields, but has never been systematically explored from a philosophical perspective, and has in fact been the source of considerable confusion in the literature.

The existence of deep-seated thematic connections between Darwinian evolutionary theory and rational choice theory is interesting in itself and deserving of close philosophical study. However, the research project does not merely seek to document or catalogue these connections, but to go further and ask why they obtain. In particular, one hypothesis to be explored is that the Darwinian process itself, i.e. the selective preservation of favoured variants in a population, will tend over time to produce organisms that behave like rational agents consciously trying to maximise a utility function. On this hypothesis, exhibiting rational behaviour – in an ‘as if’ rather than a conscious sense – is part of what it takes for an organism to be well-adapted to the environment, and thus something that natural selection should tend to produce.

If this hypothesis turns out to be correct, it offers a putative explanation for why the theory of utility-maximisation and the theory of fitness-maximisation should exhibit such striking similarities, despite their independent development and the fact that that their explanatory goals are different. (The former was devised to explain the behaviour of rational agents, the latter to explain why non-human organisms are so well adapted to their environment.) However, it cannot simply be assumed that the hypothesis in question is correct; this is something that requires careful analysis.


Project Conferences


  • The next project event is a two-day conference on Causation in Biology. It will take place in the Department of Philosophy (Cotham House), University of Bristol, 2-3 September 2015. For more information, please see the conference webpage.



  • Conference ‘Evolution, Intentionality and Information’, 29-31 May
  • Workshop ‘Foundations of Social Evolution Theory’, 19 April

Project Seminars

The project holds regular meetings, in the Philosophy Department (Cotham House, Samir's office, see details below). For further information please contact: Johannes.Martens@bristol.ac.uk.


  • January 25th: Tony Walsby (Bristol,) 'Schrodinger's Typescript'
  • February 1st: Samir Okasha (Bristol), 'Inclusive Fitness Maximization: an axiomatic approach'
  • February 8th: Reading group on Steve Frank, 'How to read the fundamental equations of evolutionary change in terms of information theory', J. Evol. Bio 2012. Paper available here: http://stevefrank.org/natSel.html
  • February 15th: Omri Tal (LSE), 'From Shannon's Axiomatic Approach to a New Sense of Biological Information'
  • March 1st: Reading group on Steve Frank, 'Partitioning the information in fitness and characters by path analysis', J. Evol. Bio 2013. Paper available here: http://stevefrank.org/natSel.html
  • March 8th: Reading group on a paper by Donaldson-Matasci, Bergstrom and Lachmann, 'The fitness value of information', Oikos 2010.
  • March 15th: Frédéric Bouchard (Montreal), 'How Research on Symbiosis Should Transform our Understanding of Adaptation' (abstract can be found at: http://aaas.confex.com/aaas/2013/webprogram/Paper8683.html)
  • March 22nd: Reading group on a paper by Bergstrom & Rosvall, 'The transmission sense of information', Biol Philos, 2011.
  • October 14th: Reading group on a paper by Lee and Chow, 'The causal meaning of Fisher's average effect': http://arxiv.org/pdf/1304.1844v1.pdf
  • October 24th: Reading group on the first three chapters of the book The Adaptive Landscape in Evolutionary Biology, edited by Svensson and Calsbeek (Oxford University Press).
  • November 7th: Reading group on a paper by Grafen, and a response by Lehmann and Rousset (both to appear in a special issue of Biology and Philosophy).
  • November 29th: Oli Lean (Bristol), “Arbitrariness in biological communication”.
  • December 5th: Reading group on a paper by Orzack on the formal Darwinism project of Alan Grafen (to appear in Biology and Philosophy)


Key information

This project is running from 1 April 2012 to 30 September 2016, and is funded by an Advanced Investigator Grant from the European Research Council.



General enquiries may be sent to the Principal Investigator, Professor Samir Okasha, samir.okasha@bristol.ac.uk.