What do animat models model?

Abstract

The practice of modelling behaviour using animats has met recent criticism. Since animats bear little structural resemblance to biological systems, it isn't clear what animat models are models of. In this paper I identify and defend a central epistemic presupposition behind animat research; the claim that modellers can acquire new knowledge about biological systems without modelling their specific underlying mechanisms. I cast the critiques of animat research offered by Webb and Bechtel as forms of a general skeptical challenge to this presupposition and show how it could be met by an appeal to multiply-realisable behaviour types. I then outline a means of specifying such types dynamically.

Keywords:

• animat
• modelling
• multiple realisability
• biology
• behaviour
• dynamical systems
• enactivism

Notes

Notes

1. The term ‘abstraction’ is potentially misleading. Abstraction suggests abstraction from something, but while Webb suggests that all generalisations from actual systems count as abstractions she also notes that an abstract model may describe ‘no existing system at all’. For the purposes of continuity I will use her terminology.

2. There is an interesting parallel between this issue and what is known as reliabilism in the philosophical literature on epistemology. Reliabilism (or more specifically, process reliabilism about justification) states that a belief that P is justified on the basis of a reason, or ground, R just in case R is a reliable indication that P is true.

3. In particular, animats provide positive information about sufficient conditions and negative information about necessary conditions. If an animat can produce behaviour X without Y, then we know that Y is unnecessary for X. It is unlikely that animats can provide positive information about the necessary conditions for behaviour.

4. Beer (2003) p. 218