Studies women and men as friends using a developmental perspective. The text examines cross-sex friendships from early childhood through to old age, then summarizes the findings and offers recommendations on how friendship between males and females can be encouraged throughout the life span. In each chapter three themes are documented and applied to the corresponding stage of life: cross-sex friendships enrich an individual’s social network in generic and unique ways; social and structural barriers interfere with the formation of cross-sex friendships in every stage of life; and cross-sex friendships affect and are affected by an individual’s ongoing social construction of self throughout the life cycle. The text can also be used as a supplemental text in graduate and undergraduate courses for the relevant disciplines.