Psychologists to explain the vicaruious retrbituion uses the concept of outgroup entitativiety, that is the perception of a group as a pure entity abstracted from the individuals it is composed of
. Furthermore people build a bridge connecting the acts of an outgroup individual and the guilt of the group members who are not personally involved but just share the membership with the perpetrator. This bridigng can be typifed as inferences of indirect commision in the act, and by inferences of omission. Indirect commision assumes that other members encouraged the antisocial act, and omission is the failure to prevent the act \cite{Lickel_2003}