Abstract
I describe my personal evolution as a modeller of behaviour, both human and (non-human) animal behaviour, using dynamic state-variable models. At first I worked in renewable resource Economics, especially the economics of marine fisheries where I collaborated extensively with Gordon R. Munro. Subsequently, in collaboration with Marc Mangel (and many field biologists) I worked in Behavioural Ecology. Mathematical models have played a major role in both of these subjects, but until recently mostly static models were used, on the grounds that dynamic (not to mention stochastic) models were too difficult to work with. I express the hope that our use of relatively simple (but not too simple) dynamic models has established the fact that such models can be extremely helpful, perhaps essential, in understanding many aspects of behaviour.