This book describes the results of thirteen years spent studying conversations between friends and speculates about the implications for a new theory of social and emotional development. The authors succinctly review the literature on the role of friendship in people's lives. They also thoughtfully delineate and clarify a number of methodological issues: naturalistic sampling, reliable and valid observations coding, sequential analysis, first vs. second order change, valid laboratory analogues, quantitative sociolinguistic techniques, and clinical applications. The notion of a support network is given an observational basis.