Beyond exaptation: The modules and metaphors program

1. Beyond exaptation:The modules and metaphors program Laurence Fiddick James Cook University

2. The adaptivist program vs. the adaptationist program Adaptivist program – focused on the reproductive consequences of traits. Traits that increase reproductive success are adaptive and held to be adaptations – the product of natural selection.

3. The adaptivist program vs. the adaptationist program Adaptationist program – focused on mechanisms that are complex and functionally integrated – bear evidence of special-design – which are held to be adaptations.

4. Different programs, different problems Adaptivist program – need to be vigilant for traits that currently increase reproductive success but lack the right evolutionary history. Adaptationist program – need to be vigilant for traits that display evidence of special design, but lack the right evolutionary history.

5. Exaptations: An adaptivist’s problem We suggest that such characters, evolved for other usages (or for no function at all), and later “coopted” for their current role, be called exaptations (Gould & Vrba, 1982, p. 6).

6. Two sources of exaptation A character, previously shaped by natural selection for a particular function (an adaptation), is coopted for a new use – cooptation. A character whose origin cannot be ascribed to the direct action of natural selection (a nonaptation), is coopted for a current use – cooptation.

7. What Gould & Vrba do NOT say They do NOT claim that randomly ordered traits cannot be exaptations. What Gould & Vrba DO say They DO claim that all exaptations have current utility.

8. A completely random, disorganized trait can be an exaptation provided that it increases current reproductive success. Exaptations: the adaptivist’s headache

9. But what causes the adaptationist to lose sleep? Exadaptations: the adaptationist’s headache Adaptations that have been largely been coopted for new applications, regardless of whether these new applications increase reproductive success.

10. Other sources of complexly organized functionality Cultural evolution? Intensive learning? Human artifice?

11. Exadaptation: How does that work? Adaptations – have an organized structure embodying a particular mode of operation (a modus operandi) that was designed for a specific set of problems in ancestral environments (a domain of application)

12. Exadaptation: How does that work? Evolution through natural selection is a slow process. Accumulated design is slow to change. Environments can change much faster

13. Exadaptation: How does that work? The modus operandi of an adaptation is a reflection of its accumulated design. An adaptation’s domain of application is in part determined by the environment in which it operates. Proper vs. actual domains

14. Exadaptation: How does that work? With environmental change, the modus operandi of an adaptation can potentially organize a different domain of inputs.

15. Exadaptations: Do they exist? Possible examples: Moral disgust (Rozin, Haidt, & McCauley, 1999) Written language (Pinker, 1994) Law (Fiddick, 2004) Mathematics (Dehaene, 1997) Music (Dissanayake, 2000) Poetry (Miall & Dissanayke, 2003) Race (Gil-White, 2001; Hirschfeld, 1996; Kurzban, Tooby, & Cosmides, 2001) Religion (Boyer, 1994; Kirkpatrick, 1999) Science (Atran, 1990) Are these exaptations?

16. …. but Possibly ... but No effort to establish that these traits increase current reproductive success. Every effort made to understand the organization of the phenomenon. The organization of the phenomenon is traced back in part to prior adaptations.

17. What would be a good example of an exaptation? Sperm bank donations – fairly high probability that one’s reproductive success will be increased by doing so but clearly an evolutionarily novel behavior.

18. Increase Reproductive Success? Yes No Music Poetry Mathematics Science Kinship Classification Manipulation Sperm Bank Donations Recycling Plastic Watching TV Exaptations

19. Increase Reproductive Success? Yes No Yes Exadaptations Complex Functionality? Music Poetry Mathematics Science No Kinship Classification Manipulation Sperm Bank Donations Recycling Plastic Watching TV Exaptations

20. A systematic program of research without a name The modules and metaphors program Moral disgust (Rozin, Haidt, & McCauley, 1999) Written language (Pinker, 1994) Law (Fiddick, 2004) Mathematics (Dehaene, 1997) Music (Dissanayake, 2000) Poetry (Miall & Dissanayke, 2003) Race (Gil-White, 2001; Hirschfeld, 1996; Kurzban, Tooby, & Cosmides, 2001) Religion (Boyer, 1994; Kirkpatrick, 1999) Science (Atran, 1990)

21. Modules An evolved faculty of mind that is flexibly, domain-specific. The proper domain of the mechanism is given by its selective history. Flexibility is brought about by changes in the mechanism’s environment which affect its actual domain of application, but not its modus operandi

22. Metaphors Taking a system of concepts and inferences from a base domain and applying them to a novel target domain. Evolutionary theory as a scientifically coherent account of base domains. Evolutionarily novel situations as possible target domains.

23. How does the program work? • Focus on a complexly organized, but evolutionarily novel trait. 2 some practitioners even explicitly note that this is what they are doing – e.g. Gil-White and Kurzban et al. when investigating race

24. How does the program work? • Focus on a complexly organized, but evolutionarily novel trait. 2) Characterize the modus operandi of the trait – how is the phenomenon organized? 3) Draw parallels with a plausible adaptation that possesses the same modus operandi. 4) Demonstrate a previously unknown aspect of the novel trait that is known to exist in the evolved trait or vice versa.

25. How does the program work? • Focus on a complexly organized, but evolutionarily novel trait. 2) Characterize the modus operandi of the trait – how is the phenomenon organized? 3) Draw parallels with a plausible adaptation that possesses the same modus operandi. 4) Demonstrate a previously unknown aspect of the novel trait that is known to exist in the evolved trait or vice versa.

26. How does the program work? • Focus on a complexly organized, but evolutionarily novel trait. 2) Characterize the modus operandi of the trait – how is the phenomenon organized? 3) Draw parallels with a plausible adaptation that possesses the same modus operandi. Ideally… 4) Demonstrate a previously unknown aspect of the novel trait that is known to exist in the evolved trait or vice versa.

27. Is it compatible with evolutionary psychology? Critics of evolutionary psychology have argued that precisely these sorts of phenomena are incompatible with and raise serious doubts about evolutionary psychology (Mithen, 1996; Chiappe, 2000). Violates evolutionary psychology’s presumed modularity.

28. Is it compatible with evolutionary psychology? Evolutionary psychologists are committed to the study of functional structure. They assume that functional structure is best explained in evolutionary terms.

29. Is it compatible with evolutionary psychology? Evolutionary psychologists are NOT committed to the view that present environments are the same as ancestral environments. Given that the domain of an adaptation’s application is in part a function of the environment in which it operates, evolutionary psychologists are NOT committed to the view that the actual domain of a module is fixed.

30. Is it compatible with evolutionary psychology? Evolutionary psychology is compatible with the possibility that novel environments can alter the actual domain of an adaptation. Evolutionary psychology is not compatible with the possibility that novel environments can alter the functional organization of an adaptation – in function preserving ways.

31. The concept of metaphor, itself, presupposes the preservation of conceptual and inferential organization from the base domain to the target domain.

32. What do evolutionary psychologists have to gain from the program? • An alternative account of expertise • A defendable boundaries to adaptationist proposals • A rich source of data

33. Face Processing

34. A B

35. A B

36. A B

37. A B

38. Kanwisher, McDermott, & Chun (1997)

39. Greebles

40. Gauthier, et al. (1999)

41. Gauthier, et al. (1999)

42. But… Abacus experts show a bilateral increase in superior frontal sulcus and superior parietal lobule activation in a digit memory task (Tanaka, et al. 2002) Expert pilots show more frontal and prefrontal activation, less visual and motor activation in an aviation track-following task (Peres, et al. 2000)

43. What do evolutionary psychologists have to gain from the program? • An alternative account of expertise • A defendable boundaries to adaptationist proposals • A rich source of data

44. Social Contract Theory (Cosmides, 1985) Proposal: humans possess an evolved, “look for cheaters” algorithm Based on evolutionary theories of reciprocal altruism (Axelrod, 1984; Axelrod & Hamilton, 1981; Trivers, 1971) Evidence: studies conducted on the Wason selection task

45. Social Contracts If you take the benefit, then you must pay the cost Two types: Personal exchanges – two parties cooperating for mutual benefit Social laws – one person granted a benefit on the basis of a societal law

46. If you take the benefit, then you must pay the cost Only personal exchanges correspond to the form of interaction modelled by evolutionary theory Personal exchanges – two parties cooperating for mutual benefit Social laws – one person granted a benefit on the basis of a societal law

47. Two possibilities • Amend the evolutionary theory • Draw a distinction between the proper domain of the adaptation (personal exchanges) and the actual domain of the adaptation (personal exchanges and social laws). Social laws as a metaphorical extension of cognitive adaptations for social exchange

48. Do NOT claim that novel expressions of the adaptation are part of its evolved function

49. What do evolutionary psychologists have to gain from the program? • An alternative account of expertise • A defendable boundaries to adaptationist proposals • A rich source of data

50. Psychological Experiments Many psychological experiments used to test adaptationist hypotheses rely upon the application of mental adaptations to evolutionarily novel situations.