Intergroup relations: the way in which people in groups perceive, think about, feel about, and act toward people in other groups. One important aspect of intergroup relations is the collective behaviour of people in a crowd. Studying people"s behaviour in crowds or studying the collective action of people when they"re part of a large mass can be difficult. This is the case because there are many factors that influence people"s behaviour in crowds, including. Each individual"s motivation and goals in being part of the crowd, The presence of others who share those motivations and goals, The presence of others who oppose them, The cues that are present in the environment, One of the earliest theories of crowd behaviour was suggested by gustav le bon. He observed riots in france and argued that when people become part of a crowd they descend several rungs on the ladder of civilization people act instinctively and become irrational.