Much has been made of the complex social arrangements that girls and women navigate, but little scholarly or popular attention has focused on what friendship means to men. Drawing on in-depth interviews with nearly 400 men, therapist and researcher Geoffrey L. Greif takes readers on a guided tour of male friendships, explaining what makes them work, why they are vital to the health of individuals and communities, and how to build the kinds of friendships that can lead to longer and happier lives. Another 120 conversations with women help map the differences in what men and women seek from friendships and what, if anything, men can learn from women's relationships. The guiding feature of the book is Greif's typology of male friendships: he dispels the myth that men don't have friends, showing that men have *must, trust, just,*and rust friends. A must friend is the best friend a man absolutely must call with earthshaking news. A trust friend is liked and trusted but not necessarily held as close as a must friend. Just friends are casual acquaintances, while rust friends have a long history together and can drift in and out of each other's lives, essentially picking up where they last left off. Understanding the role each of these types of friends play across men's lives reveals fascinating developmental patterns, such as how men cope with stress and conflict and how they make and maintain friendships, and how their friends keep them active and happy. Through the lively words of men themselves, and detailed profiles of men from their twenties to their nineties, readers may be surprised to find what friendships offer men--as well as their families and communities--and are sure to learn what makes their own relationships tick.