The different verbal and nonverbal signals used in conversation have been studied, and the functions of such factors as gaze, gesture, and tone of voice are analyzed in social-interaction studies. Social interaction is thus seen to consist of closely related sequences of nonverbal signals and verbal utterances. Gaze has been found to perform several important functions. Laboratory and field studies have examined helping behaviour, imitation, friendship formation, and social interaction in psychotherapy.

Among the theoretical models developed to describe the nature of social behaviour, the stimulus–response model (in which every social act is seen as a response to the preceding act of another individual) has been generally found helpful but incomplete. Linguistic models that view social behaviour as being governed by principles analogous to the rules of a game or specifically to the grammar of a language have also attracted adherents. Others see social behaviour as a kind of motor skill that is goal-directed and modified by feedback (or learning), while other models have been based on the theory of games, which emphasizes the pursuit and exchange of rewards and has led to experiments based on laboratory games.

Small social groups

All small social groups do not function according to the same principles, and, indeed, modes of social activity vary for particular kinds of groups (e.g., for families, groups of friends, work groups, and committees).

Earlier research was concerned with whether small groups did better than individuals at various tasks (e.g., factory work), while later research has been directed more toward the study of interaction patterns among members of such groups. In the method known as sociometry, members nominate others (e.g., as best friends) to yield measures of preference and rejection in groups. Others have studied the effects of democratic and authoritarian leadership in groups and have greatly extended this work in industrial settings. In research on how people respond to group norms (e.g., of morality or of behaviour), most conformity has been found to the norms of reference groups (e.g., to such groups as families or close friends that are most important for people). The emergence and functioning of informal group hierarchies, the playing of social roles (e.g., leader, follower, scapegoat), and cohesiveness (the level of attraction of members to the group) have all been extensively studied. Experiments have been done on processes of group problem solving and decision making, the social conditions that produce the best results, and the tendency for groups to make risky decisions. Statistical field studies of industrial work groups have sought the conditions for greatest production effectiveness and job satisfaction.

Social organizations

Such organizations as businesses and armies have been studied by social surveys, statistical field studies, field experiments, and laboratory experiments on replicas of their social hierarchies and communication networks. Although they yield the most direct evidence, field experiments present difficulties, since the leaders and members of such organizations may effectively resist the intervention of experimenters. Clearly, efforts to try out democratic methods in a dictatorship are likely to be severely punished. Investigators can study the effects of role conflict resulting from conflicting demands (e.g., those from above and below) and topics such as communication patterns in social organizations. Researchers also have studied the sources of power and how it can be used and resisted. They consider the effectiveness of different organizational structures, studying variations in size, span of control, and the amount of power delegation and consultation. In factories, social psychologists study the effects of technology and the design of alternative work-flow systems. They investigate methods of bringing about organizational change (e.g., in the direction of improving the social skills of people and introducing industrial democracy).