Psychology is designed to meet scope and sequence requirements for the single-semester introduction to psychology course. The book offers a comprehensive treatment of core concepts, grounded in both classic studies and current and emerging research. The text also includes coverage of the DSM-5 in examinations of psychological disorders. Psychology incorporates discussions that reflect the diversity within the discipline, as well as the diversity of cultures and communities across the globe.Senior Contributing AuthorsRose M. Spielman, Formerly of Quinnipiac UniversityContributing AuthorsKathryn Dumper, Bainbridge State CollegeWilliam Jenkins, Mercer UniversityArlene Lacombe, Saint Joseph's UniversityMarilyn Lovett, Livingstone CollegeMarion Perlmutter, University of Michigan

By the end of this section, you will be able to:Define operant conditioningExplain the difference between reinforcement and punishmentDistinguish between reinforcement schedules

The puzzle box is the laboratory device that Edward L. Thorndike invented in order to study instrumental or operant conditioning in cats. Hungry cats were individually placed into a box that could be opened by the animal via a device such as a latch. Once outside of the box, the cats gained access to food (a positive reinforcer). Thorndike found that the cats took less and less time to get out of the box the more trials of training had been given. He referred to this reinforcement of latch opening as documenting the Law of Effect.