Andaman Islanders,Pygmies, and an extension of Horn's model

Horn's model is generalized to state that the optimal pattern of distribution for foragers will correlate with the degree of resource patchiness; in particular (1) where resource attributes are less patchy, the optimal distribution for foragers is to be dispersed, and (2) where resource attributes are more patchy, the optimal distribution for foragers is to be aggregated. Optimality is assessed as the minimum round-trip distance from the forager's home base to a resource item. Patchiness is assessed according to the state taken by any of four resource attributes: dispersion (in space), supply (in time), particle size, and lasting properties. Horn's original contrast between (1) stable and evenly dispersed resources, and (2) mobile and clumped resources is shown to have been internally contradictory; that is, the optimal distribution for foragers would have been the same in both cases.