Reinforcement and Behavior brings together research findings and views of a number of investigators on the principles of learning and reinforcement. Their work has challenged the more traditional interpretations of the nature of the reinforcement process. Within the book, the chapters are organized from a molar level of analysis to a molecular one, not only to reflect the diversity of strategies that are being brought to bear on the problem, but also to show that the research on the nature of reinforcement transcends lines of scientific disciplines and that many different levels of analysis contribute to our understanding of the phenomenon. The first and last chapters give historical perspective to the remainder of the book by reviewing the contributions of a number of individuals who have dealt with the problem in their own work and by pointing out some of the major issues on the molar level that are still unresolved. The remaining chapters can be roughly divided into two categories. One examines the consequences of rewards on behavior in order to specify the limits of their operations and the variables which predispose organisms to be responsive to the consequences of rewards. The other deals with the neural mechanisms which underlie reinforcement and learning.