In recent work, we have employed the demonstrator-observer paradigm developed by Strupp and Levitsky (1984). The paradigm is based on the interaction between two animals; one serving as a demonstrator, which serves as part of the experimental paradigm and the other as an observer, which serves as the experimental animal in which changes in behavior are assessed. Social behaviors peak during adolescence, and adolescent rats engage in distinctive forms of social behavior, including play behavior, social investigation and social contact (Panksepp, 1981; Pellis, Field, Smith and Pellis, 1997; Pellis and Pellis, 1997; Varlinskaya, Spear and Spear, 2001, Varlinskaya and Spear, 2002). It has been suggested that social play represents a separate category of behavior that is different from adult typical social, sexual and aggressive types of behaviors (for review see Vanderschuren et al., 1997). While play behavior peaks during adolescence, as adults mature their behavior becomes more aggressive (Meaney and Stewart, 1981). These data demonstrate that the peak in social behavior is present during the adolescent period of development, and not in younger or older animals. Therefore, assessing the influence of social behaviors on passive social learning specifically during adolescence is appropriate.
