Andaman Islanders, Pygmies, and an Extension of Horn's Model

Horn's model is generalized to state that the "optimal" pattern o f distribution for foragerswill correlate with the degree o f 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 o f f our 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.