In the World Library of Psychologists series, international experts themselves present career-long collections of what they judge to be their finest pieces - extracts from books, key articles, salient research findings, and their major practical theoretical contributions. In this fascinating volume, Harry Reis reflects on a career that has earned him an international reputation as an eminent scholar and pioneer in the field of relationship science, through a selection of papers that illustrate the foundational theme of his research career: the importance of relationships for human well-being. The book charts the development of research in social psychology and relationship science through three key themes; from the relationship context of human behaviour, through to the value of studying behaviour in its natural context, and finally intimacy and responsiveness in close relationships. Also featuring a newly written introduction by the author contextualizing the selections and offering an intimate overview of his career, this collection of key publications offers a unique and compelling insight into decades of groundbreaking work, making it an essential resource for all those engaged or interested in the psychology of relationships and well-being.