The most important condition to increase groups performance is psychological safety. Members of the best performing groups at Google 1) spoke roughly the same amount (equal conversational turn-taking) 2) and scored high on social sensitivity test (Reading the Mind in the Eyes test – guessing what people are thinking or feeling from photos of people’s eyes)
"As the researchers studied the groups, however, they noticed two behaviors that all the good teams generally shared. First, on the good teams, members spoke in roughly the same proportion, a phenomenon the researchers referred to as ‘‘equality in distribution of conversational turn-taking.’’ On some teams, everyone spoke during each task; on others, leadership shifted among teammates from assignment to assignment. But in each case, by the end of the day, everyone had spoken roughly the same amount. ‘‘As long as everyone got a chance to talk, the team did well,’’ Woolley said. ‘‘But if only one person or a small group spoke all the time, the collective intelligence declined.""
"the good teams all had high ‘‘average social sensitivity’’ — a fancy way of saying they were skilled at intuiting how others felt based on their tone of voice, their expressions and other nonverbal cues. One of the easiest ways to gauge social sensitivity is to show someone photos of people’s eyes and ask him or her to describe what the people are thinking or feeling — an exam known as the Reading the Mind in the Eyes test. People on the more successful teams in Woolley’s experiment scored above average on the Reading the Mind in the Eyes test. They seemed to know when someone was feeling upset or left out. People on the ineffective teams, in contrast, scored below average. They seemed, as a group, to have less sensitivity toward their colleagues."
Google's Re:work website sumarizes biggest findings of Project Aristotle.
Of the five key dynamics of effective teams that the researchers identified, psychological safety was by far the most important. Organizational behavioral scientist Amy Edmondson of Harvard first introduced the construct of “team psychological safety” and defined it as “a shared belief held by members of a team that the team is safe for interpersonal risk taking.”
Team members get things done on time and meet expectations.
High-performing teams have clear goals, and have well-defined roles within the group.