Organizational commitment is often explained by calculative-instrumental approach, such that when organization satisfy their members' needs the result is likely to be a heightened level of members' commitment. However, since the economic crises in the recent years this mission becomes more and more difficult. This book investigates how psychological process of the self (i.e. realization of personal values and expression of self-identities) is contributing to organizational commitment, without the need for economic investment. The author builds on the theory of congruence, or fit, between a person’s individual characteristics and the opportunities that his or her organization provides. Guided by an inter-disciplinary approach, this book develops and tests an integrative theoretical model that allows a detailed look about the process by which three types of person-organizations Fit: needs-fulfillment, values-realization, self-identities-its expression, relates to three manifestations of commitment: Identification, contribution, presence, in three prototypes of organization: Business/work, ideological/voluntary, community/social.