Casa Robino

Group formation starts with a psychological bond between individuals. The social cohesion approach suggests that group formation comes out of bonds of interpersonal attraction.[2] In contrast, the social identity approach (rooted in Social Identity Theory and Self-categorization Theory) suggests that a group starts when a collection of individuals perceive that they share some social category (‘smokers’, ‘nurses,’ ‘students,’ ‘hockey players’), and that interpersonal attraction only secondarily enhances the connection between individuals.[2] Additionally, from the social identity approach, group formation involves both identifying with some individuals and explicitly not identifying with others. So to say, a level of psychological distinctiveness is necessary for group formation. Through interaction, individuals begin to develop group norms, roles, and attitudes which define the group, and are internalized to influence behavior.[13]
Emergent groups arise from a relatively spontaneous process of group formation. For example, in response to a natural disaster, an emergent response group may form. These groups are characterized as having no preexisting structure (e.g. group membership, allocated roles) or prior experience working together.[14] Yet, these groups still express high levels of interdependence and coordinate knowledge, resources, and tasks