The free food (contrafreeloading) phenomenon: A review and analysis Steve R. Osborne OriginalPaper Pages: 221 - 235
Acquisition of barpressing in rats following experience with response-independent food Kimbal L. WheatleyRobert L. WelkerRaymond C. Miles OriginalPaper Pages: 236 - 242
Lack of effect of specific sodium hunger on learned aversions to sodium and sucrose Ava M. TrentJames W. Kalat OriginalPaper Pages: 243 - 246
The effect of discrimination training on the response rate and response duration of the rat Arthur GutmanJames R. Sutterer OriginalPaper Pages: 247 - 252
Circadian rhythms of tonic immobility in the rat: Evidence of an endogenous mechanism Charles W. HennigWilliam P. Dunlap OriginalPaper Pages: 253 - 258
Discriminated and nondiscriminated avoidance conditioning of the rearing response in rats Akira ShishimiHiroshi Imada OriginalPaper Pages: 259 - 264
Absolute versus relative class conceptual behavior in squirrel monkeys (Saimiri sciureus) Roger K. ThomasThomas N. Crosby OriginalPaper Pages: 265 - 271
Functional differentiation of adjunctive drinking and wheel running in rats John PenneyJonathan Schull OriginalPaper Pages: 272 - 280
Immunization and helplessness phenomena in the rat in a nonaversive situation G. P. MullinsA. H. Winefield OriginalPaper Pages: 281 - 284
Adjunctive drinking during variable and random-interval food reinforcement schedules J. R. MillensonRobert B. AllenSteven Pinker OriginalPaper Pages: 285 - 290
Early experience and the development of predatory and intraspecific aggression in mice John P. WheltonMichael O’Boyle OriginalPaper Pages: 291 - 296
Sex differences in rats’ stationary exploration as a function of stimulus and environmental novelty P. A. Russell OriginalPaper Pages: 297 - 302
Reliability and sources of control of preference for signaled shock Ralph R. MillerNancy A. MarlinAlvin M. Berk OriginalPaper Pages: 303 - 308
Second-order conditioning: The importance of stimulus overlap on second-order trials Richard MaisiakPeter W. Frey OriginalPaper Pages: 309 - 314
Excitatory and inhibitory conditioning following uncorrelated presentations of CS and UCS A. G. BakerN. J. MacKintosh OriginalPaper Pages: 315 - 319
Correction of a paper by Mitchell, Scott, and Mitchell Samuel H. Revusky Notes and Comment Pages: 320 - 320