Openness to Experience is one of the 5 broad factors that subsume most personality traits. Openness is usually considered an intrapsychic dimension, defined in terms of characteristics of consciousness. However, different ways of approaching and processing experience lead to different value systems that exercise a profound effect on social interactions. In this article, the author reviews the effects of Openness versus Closedness in cultural innovation, political ideology, social attitudes, marital choice, and interpersonal relations. The construct of Openness and its measures could profitably be incorporated into research conducted by social psychologists, sociologists, political scientists, anthropologists, and historians.