Leon Festinger's theory of cognitive dissonance has been widely recognized for its important and influential concepts in areas of motivation and social psychology. The theory of dissonance is here applied to the problem of why partial reward, delay of reward, and effort expenditure during training result in increased resistance to extinction.
The author contends that a state of impasse exists within learning theory largely because some of its major assumptions stand in apparent opposition to cetain well-established experimental results. The book puts forward a new theory that seems to reconcile these data and assumptions. This new theory can account for data with which other theories have difficulty: it integrates empirical phenomena that have been regarded as unrelated, and it is supported by the results of experiments designed specifically to test its implications. These experiments are fully described in the text.

2011 reprint of 1956 First edition. Full facsimile of the original edition, not reproduced with Optical Recognition Software. When Prophecy Fails [1956] is a classic text in social psychology authored by Leon Festinger, Henry Riecken, and Stanley Schachter. It chronicles the experience of a UFO cult that believed the end of the world was at hand. In effect, it is a social and psychological study of a modern group that predicted the destruction of the world, and the adjustments made when the prediction failed to materialize. "The authors have done something as laudable as it is unusual for social psychologists. They espied a fleeting social movement important to a line of research they were interested in and took after it. They recruited a team of observers, joined the movement, and watched it from within under great difficulties until its crisis came and went. Their report is of interest as much for the method as for the substance."-Everett C. Hughes, The American Journal of Sociology.

2012 reprint of 1956 First edition. Full facsimile of the original edition, not reproduced with Optical Recognition Software. When Prophecy Fails 1956] is a classic text in social psychology authored by Leon Festinger, Henry Riecken, and Stanley Schachter. It chronicles the experience of a UFO cult that believed the end of the world was at hand. In effect, it is a social and psychological study of a modern group that predicted the destruction of the world, and the adjustments made when the prediction failed to materialize. "The authors have done something as laudable as it is unusual for social psychologists. They espied a fleeting social movement important to a line of research they were interested in and took after it. They recruited a team of observers, joined the movement, and watched it from within under great difficulties until its crisis came and went. Their report is of interest as much for the method as for the substance."-Everett C. Hughes, The American Journal of Sociology.

2012 reprint of 1956 First edition. Full facsimile of the original edition, not reproduced with Optical Recognition Software. When Prophecy Fails 1956] is a classic text in social psychology authored by Leon Festinger, Henry Riecken, and Stanley Schachter. It chronicles the experience of a UFO cult that believed the end of the world was at hand. In effect, it is a social and psychological study of a modern group that predicted the destruction of the world, and the adjustments made when the prediction failed to materialize. "The authors have done something as laudable as it is unusual for social psychologists. They espied a fleeting social movement important to a line of research they were interested in and took after it. They recruited a team of observers, joined the movement, and watched it from within under great difficulties until its crisis came and went. Their report is of interest as much for the method as for the substance."-Everett C. Hughes, The American Journal of Sociology.

2012 reprint of 1956 First edition. Full facsimile of the original edition, not reproduced with Optical Recognition Software. When Prophecy Fails 1956] is a classic text in social psychology authored by Leon Festinger, Henry Riecken, and Stanley Schachter. It chronicles the experience of a UFO cult that believed the end of the world was at hand. In effect, it is a social and psychological study of a modern group that predicted the destruction of the world, and the adjustments made when the prediction failed to materialize. "The authors have done something as laudable as it is unusual for social psychologists. They espied a fleeting social movement important to a line of research they were interested in and took after it. They recruited a team of observers, joined the movement, and watched it from within under great difficulties until its crisis came and went. Their report is of interest as much for the method as for the substance."-Everett C. Hughes, The American Journal of Sociology.

The study reported in this volume grew out of some theoretical work, one phase of which bore specifically on the behavior of individuals in social movements that made specific (and unfulfilled) prophecies. We had been forced to depend chiefly on historical records to judge the adequacy of our theoretical ideas until we by chance discovered the social movement that we report in this book. At the time we learned of it, the movement was in mid-career but the prophecy about which it was centered had not yet been disconfirmed. We were understandably eager to undertake a study that could test our theoretical ideas under natural conditions. That we were able to do this study was in great measure due to the support obtained through the Laboratory for Research in Social Relations of the University of Minnesota. This study is a project of the Laboratory and was carried out while we were all members of its staff. We should also like to acknowledge the help we received through a grant-in-aid from the Ford Foundation to one of the authors, a grant that made preliminary exploration of the field situation possible.

2009 reprint of 1956 First edition. When Prophecy Fails [1956] is a classic text in social psychology authored by Leon Festinger, Henry Riecken, and Stanley Schachter. It chronicles the experience of a UFO cult that believed the end of the world was at hand. In effect, it is a social and psychological study of a modern group that predicted the destruction of the world, and the adjustments made when the prediction failed to materialize. "The authors have done something as laudable as it is unusual for social psychologists. They espied a fleeting social movement important to a line of research they were interested in and took after it. They recruited a team of observers, joined the movement, and watched it from within under great difficulties until its crisis came and went. Their report is of interest as much for the method as for the substance."-Everett C. Hughes, The American Journal of Sociology.

For more than a million years, man's utter dependence on technology has been producing a host of intricate problems. For example, we steadily reduce the need for human labor while finding ways to increase life expectancy. We mass produce the automobile without grasping the harsh effects it leaves on the environment. The Human Legacy concerns the evolution and development of man-physically, socially, psychologically-into the latest version of the species we see around us today. The author paints an intriguing picture of man, living in complex societies and trying to solve the unanticipated consequences of action.

For more than a million years, man's utter dependence on technology has been producing a host of intricate problems. For example, we steadily reduce the need for human labor while finding ways to increase life expectancy. We mass produce the automobile without grasping the harsh effects it leaves on the environment. The Human Legacy concerns the evolution and development of man-physically, socially, psychologically-into the latest version of the species we see around us today. The author paints an intriguing picture of man, living in complex societies and trying to solve the unanticipated consequences of action.