Greater than the sum of its parts (Image: WestEnd61/Rex Features)

If you’re a headhunter looking for someone to work in a group, you might want to stop chasing down the most intelligent candidates. Group intelligence depends less on how smart individuals are and more on their social sensitivity, ability to take turns speaking, and the number of women in the group.

So says Anita Woolley from Carnegie Mellon University in Pittsburgh, Pennsylvania, and colleagues, having measured group intelligence and the influences that individuals have on it.

To measure group intelligence, Woolley placed 699 people into teams of two to five and asked them to carry out simple tasks including brainstorming, moral reasoning, puzzle-solving, typing and negotiating.


The groups were evaluated on how well they did, and given an overall score for group intelligence.

Individual intelligence as measured by IQ tests relies on the premise that people who are good at one task are generally good at several, which suggests that an underlying “general intelligence” exists. Although somewhat controversial, such tests can be used to predict how well a person will do in more complex tests. Woolley’s team found a similar general intelligence in groups, and it was also a successful predictor of how well that group would perform at subsequent, more complex tasks.

No I in team

To find out who, or what, was making the largest contribution to a group’s overall intelligence, Woolley then measured factors such as each individual’s intelligence, personality, social sensitivity, group satisfaction and motivation using various psychometric tests.

Woolley says she was surprised to find that neither the average intelligence of the group members nor the intelligence of the smartest member played much of a role in the overall group intelligence. Social sensitivity – measured using a test in which participants had to identify another person’s feelings by looking at photographs of their eyes – was by far the most important factor.

Girl power

The team also found that groups in which members took turns speaking were more collectively intelligent, as were groups containing a majority of women. Woolley thinks this may be because the women had higher levels of social sensitivity than the men.

“What it suggests is that if you don’t know the social sensitivity of a group, it is a better bet to include females than not,” says Woolley.

“The paper extends previous research in showing that versatile high-impact teams aren’t always driven by the highest or lowest-IQ member, but by team processes,” says Brian Uzzi from Northwestern University in Evanston, Illinois. However, he says the finding on gender is surprising, because it goes against previous research showing that women in mixed-gendered groups often feel unheard.

Woolley says that selection processes used to form groups in the workplace may need to be re-evaluated, shifting the focus from individual intelligence to collaboration skills.

Journal reference: Science, DOI: 10.1126/science.1193147