Much of this book is concerned with the ‘social dimension’ of social psychology. This chapter follows the trend. It attempts to bring together three issues which have all been, in one way or another, at the forefront of several of the preceding chapters. All three appear in the title of the chapter. The main reason for bringing them together is that they are all of direct relevance to collective behaviour, a subject left severely alone by most of ‘mainstream’ social psychology. The three themes are concerned, by definition, with collective behaviour. In the case of intergroup relations, this is so because these relations do not empirically exist unless some clearly identifiable uniformities can be found in the attitudes and behaviour displayed by members of one social group towards the members of another. In the case of social myths, they are neither social nor myths if they are not widely diffused within a social or cultural context. They filter the information received about people and events and may determine in this way important common features of social attitudes and social behaviour. In the case of social justice, we are dealing again with collective phenomena, since the concern is with the social psychology of justice or injustice as it refers to relations between large-scale socially defined and evaluated categories of people rather than with interpersonal processes, to which Chapter II of this book, by Mikula, is devoted.