Key Points

A group is an organized system of two or more individuals who are interacting, interdependent, share common motives, have role relationships, and follow norms that regulate their behavior.

A group has structure, interdependence, and a sense of belonging, like a family. A crowd is a collection of people at one place by chance, lacking structure or interdependence.

Individuals join groups to satisfy needs such as security, status, self-esteem, belongingness, goal achievement, and gaining knowledge or information.

The formation of groups is facilitated by three main conditions: proximity (physical closeness), similarity (shared attitudes and interests), and common motives or goals.

Tuckman proposed five developmental stages for groups: Forming (uncertainty), Storming (intragroup conflict), Norming (developing norms), Performing (achieving goals), and Adjourning (disbanding).

Four important elements of group structure are Roles (expected behaviors), Norms (unspoken rules), Status (relative social position), and Cohesiveness (togetherness and mutual attraction).

Primary groups like family are characterized by close, face-to-face interaction and emotional bonds. Secondary groups like political parties are more impersonal, and membership is a matter of choice.

Formal groups, like a company, have explicitly stated functions, rules, and defined roles. Informal groups are not based on rules and are characterized by close relationships among members.

The 'ingroup' refers to one's own group ('we'), which is typically viewed favorably. The 'outgroup' refers to another group ('they'), which is often perceived negatively in comparison.

Conducted by Tajfel, these experiments showed that people will favor their own group (ingroup) even when the groups are formed on flimsy or arbitrary criteria, demonstrating ingroup bias.

Coined by Irving Janis, groupthink occurs when a cohesive group's desire for unanimity overrides realistic appraisal of alternatives, leading to irrational decision-making.

Social loafing is a reduction in individual effort when working on a collective task where individual contributions are pooled and not evaluated separately. An example is a team in a tug-of-war game.

Social loafing can be reduced by making each person's efforts identifiable, increasing the importance of the task, and strengthening group cohesiveness.

Group polarisation is the tendency for groups to make decisions that are more extreme than the initial inclination of their members. The group's initial position becomes stronger after discussion.

Polarisation occurs because members hear new supporting arguments, feel their view is validated by others (bandwagon effect), and conform to the perceived ingroup view.

Teams are a special type of group where members have complementary skills and are mutually accountable for a common purpose. In teams, both individual contribution and teamwork matter, creating positive synergy.