"This enlarged second edition is indeed a welcome and excellent addition to the literature on a phenomenon that affects us all in many ways, obvious and less obvious, as we wend our way through the mysteries and vagaries of interacting in groups Social Psychological Review How do groups function? How are people changed or influenced or affected by the groups they belong to? What similarities can we find across groups of different types, in different situations? Social groups have great influence on our thoughts, decisions and behaviour from our infancy until our deaths. Family groups, work groups, ethnic groups and our friendship networks all shape our perceptions, thoughts and actions, as well as our feelings about ourselves. In this thorough introduction to the social psychological study of group processes, the authors have considerably updated their highly successful first edition. The new edition develops the existing coverage of topics such as social influence, extreme behaviour in groups, group productivity, social dilemmas, group decision-making and inter-group conflict. It also provides additional chapters examining research and theory regarding social support, and electronic groups. This authoritative text will familiarize the reader with current theory and the latest findings, exploring the significance and application of group research for our everyday lives.