Minority Influence: Social relations are antagonistic social forces that societies want to preserve their power and social status and others aspire to improve their vida.S.Moscovici investigated how minority groups are able to switch to mayoría.Realizó various experimental investigations: Consistency: the minority has to be consistent and persistent security transmitting ideas to defend their ideas and their actions with conviction - Flexibility: the consistency can be maintained rigid or flexible - Defections of the majority: the minority can break the social consensus proposals against majority rule - Fighting psychologizing: some groups are fighting the minority majority without regard to their ideas and proposals using the Ad hominem fallacy. Groups. The human groups are many and varied with different structure and organization, sometimes flexible and sometimes rigid. Characteristics of the group now has a great importance to know the inner workings of the groups and the dynamics of intergroup relations. - Common objectives: are defined by a deficiency state and achieve a new situation from that gap - Group structure: it is the organization that takes the group to be established and developed their activities. (Status: is the position of each member within the group and contributes to its operation - Role: is the behavior expected of a person segúnsu status) - Standards: A set of rules and procedures governing the behavior and attitudes of group members - Values and beliefs ; they share ideas and beliefs, values and attitudes, an ideology that governs their relationships and helps to maintain group cohesion - The air group: refers to the mood and feelings of a group, which vary their interactions; - Communication group: forms of communication, understanding and mastery of the social environment - Types of groups: size (large / small), temporary (temporary / permanent), origin of the affiliation (primary / actual side) and level of formality (formal / informal ) Groupthink. Irving Janis identified eight symptoms of groupthink: 1.Ilusión of invulnebilidad: muxos groups develop excessive optimism blinds them to see the dangers, when making important decisions; 2.Creencia unquestioned in the morality of the group: Kennedy's advice luxaba thought against the evil forces of communism; 3.Estereotipos common: they believe their evil enemies to negotiate, too weak or lacking intelegincia to defend; 4.Racionalización collective collectively reject the challenges to justify their decisions and use lie if necessary in defense of their interests;