Author: Charles Duhigg / New York Times

Studied 180 teams to try and understand why some are effective. Effective teams were as diverse as the people in them. Eventually hit on the insight that understanding and influencing group norms was key. The group norms should ideally circle around these 5 ideas: 

1. Psychological Safety. Can you take risks without judgement?

2. Dependability. Do colleagues have each other's backs?

3. Clarity. Is the team working in the same direction?

4. Impact. Does the team believe if the work matters?

5. Meaning. Has the individual found meaning in the work

In good teams, people speak roughly the same proportion and fight to ensure everyone is represented, indicating higher than average social sensitivity. This indicates that the way people treat one another is the key to optimising group performance. Here is a great short video on psychologal safety.