Are socially acquired behaviours irreversible?

Norway rat subjects were exposed for either 3 or 10 days to conspecific demonstrators eating a cinnamon-flavoured, protein-deficient diet. While in contact with their demonstrators, and for several days thereafter, subjects were offered a choice between the cinnamon-flavoured, protein-deficient diet that their demonstrators were eating and a less palatable, nutmeg-flavoured, protein-rich diet. While subjects were in contact with their respective demonstrators they ate little protein-rich diet; during the 7 days immediately following removal of demonstrators from the experiment, subjects learned to eat sufficient amounts of protein-rich diet to permit normal growth. The results indicate that effects of social influence on food choice are transitory. They suggest that the time scale on which animals learn individually to modify socially acquired behaviour is considerably shorter than usually considered in discussions of quantitative models of the evolution of social learning processes.