Major benefits of living in groups include predation avoidance and increasing foraging efficiency (Hamilton 1971). From an individual´s point of view, foraging efficiency in a group can be increased either by observing conspecifics to acquire knowledge how to find and/or disclose food (social learning at the individual level or cultural transmission at the population level) or by the exploitation of others‚ efforts in finding food (scrounging or co-feeding). Observational learning and scrounging occurs in various ways depending on the social and ecological conditions as well as the individual‚s cognitive abilities. Therefore, foraging efficiency is probably a major selection pressure for the evolution of cognitive skills in the social domain (social intelligence theory). Even though empirical and theoretical work is quite advanced, there is no comprehensive theory combining both scrounging and social learning. This would be a significant step towards a synthetic theory of social systems. Empirical data collected during my PhD with greylag geese, Anser anser, provide a base to link the producer-scrounger theory with the social learning theory. Basically, this is an attempt to understand under which conditions an individual decides whether to scrounge or to learn to produce a certain resource and whether and how knowledge can be established as a tradition in a population of overlapping generations (cultural inheritance). Computational simulation and a comparative empirical approach are necessary to develop a model, which can be employed to predict diffusion dynamics of new behaviours through populations, determining how particular processes of social interaction affect the spread of the behaviour. They could also be used to help interpret empirical data, to establish, for instance, whether the spread of behaviour results from asocial or social learning or whether information spreads through some sub-sections of the population faster than others. Finally, developing these models should help to trace the evolution of cognitive skills in various social systems, what may also be useful to interpret the spread of cultural traits and ideas (memes) through human populations.