[The development of theories of avoidance learning and its application to behavioral pharmacology]

How the development of theories changed the definition of avoidance behavior was discussed. Three major theories of avoidance learning; the two-process theory, the species-specific defense reactions hypothesis, and the cognitive expectancy theory were reviewed. Very few innovations were brought to the experimental apparatuses and procedures by which these theories were tested. The paradigms have been applied without any theoretical considerations. Therefore, I claim here that the modification or renewal of experimental paradigms will be needed to make suitable animal models for psychopharmacology.