Originally published in 1957, this book presented an up-to-date account of psychological research into human social behaviour of the time. There are chapters on interaction between pairs of people, behaviour in small social groups, and human relations in industry. The author avoided the adoption of any particular theoretical position, and concentrated on the established empirical findings of the time. The results of several hundred investigations are summarised and compared, so that the principal generalisations which emerge can be seen. Stress is placed on rigorous methods of research, and a critical account is given of current techniques of social research, showing the importance of experimental and statistical methods. Careful consideration is given to the danger of the investigator disturbing what is being investigated. Use is made of recent ideas about theory and explanation, and the different kinds of theory used in experimental psychology were considered for the first time as possible ways of accounting for group behaviour. This book was intended not only for students of psychology and of the other social sciences, but also for industrialists, administrators and indeed all who were interested in the laws underlying social behaviour. Today it can be read and enjoyed in its historical context.