The final property of groups that we consider is diversity in the group’s membership. Overall, studies identify both costs and benefits from group diversity. Diversity appears to increase group conflict, especially in the early stages of a group’s tenure; this often lowers group morale and raises dropout rates. Surface-level diversity—in observable characteristics such as national origin, race, and gender—alerts people to possible deep-level diversity—in underlying attitudes, values, and opinions.

Surface-level diversity may subconsciously cue team members to be more open-minded in their views. Although differences can lead to conflict, they also provide an opportunity to solve problems in unique ways. If members can weather their differences, over time diversity may help them be more open-minded and creative and to perform better. One possible side effect in diverse teams is faultlines, or perceived divisions that split groups into two or more subgroups based on individual differences such as sex, race, age, work experience, and education.

Recent work indicates they can be strategically employed to improve performance.