Pavlov's words presaged a twentieth century development for study of human behavioural disorders: Animal learning models. In essence, animal modeling involves induction of disorders analogous to naturally occurring human psychopathologies in animal subjects. The goal, of course, is illumination of cause, cure, and prevention of human disorders. Historically, although Pavlov's (1941, 1966) discovery of “experimental neurosis” in dogs generated initial enthusiasm for animal modeling, the approach later fell into disrepute probably because the early animal experimentation was rather poor (McKinney, 1974). The experimental analyses of the apparently maladaptive animal behaviours were reasonably thorough, but the claim that they represented and/or analyzed some form of naturally occurring disorder was usually unconvincing. Currently, however, a resurgence of interest in the method of animal modeling coupled with increased concern by investigators to set down ground rules for evaluation of animal models is apparent in the recent compilation of several books on the subject (two still in press): Experimental psychopathology: Recent research and theory, Psychopathology: Experimental models, and Relevance of the Psychopathological animal model to the human.