People think and act differently as group members than as individuals. Because groups influence the behavior, attitudes, and motives of their members, it’s important for managers to understand how and why that happens. The members use the group’s standards or comparison points when making judgments and evaluations. A person who is a member of a group already is distinguished in certain ways from a person who is simply one individual employee in a collection of employees who happen to be in the same place at the same time. The established members direct efforts at new members to educate them, and to produce “appropriate” values and behavior. Multiple-group memberships often provide checks and balances that can be highly functional to society and organizations alike, even though they sometimes cause pain for individuals and conflict within organizations. Cohesion is a key dimension of group life that must be developed to some optimal level for each group’s needs.