title: Two-factor theory has strong empirical evidence of validity.
abstract: Traditional two-factor theory is supported by parallels in the clinical literature. Theoretical problems with two-factor theory are obviated by the role of safety signals, which serve as positive conditioned reinforcers and retard the extinction of conditioned fear.
authors.affiliation: Department of Psychology, University of California, San Diego, La Jolla 92093-0109, USA. bawilliams@ucsd.edu
authors.forename: B A
authors.initials: BA
authors.lastname: Williams
mesh_terms: D000818:Animals; D001070:Appetitive Behavior; D001362:Avoidance Learning; D003216:Conditioning, Operant; D006380:Helplessness, Learned; D006801:Humans; D009042:Motivation; D011582:Psychological Theory; D012055:Reinforcement Schedule