It makes intuitive sense that groups of people can accomplish more than individuals working alone, and this is borne out by the data. In this study for instance, where groups of different sizes were asked to collaborate on a crisis management scenario, increases in team size led consistently to improved performance, from individuals right up to groups of 32.
Error bars show standard errors.
Source: Mao A, Mason W, Suri S, Watts DJ (2016) An Experimental Study of Team Size and Performance on a Complex Task. PLoS ONE 11(4): e0153048. https://doi.org/10.1371/journal.pone.0153048
This occurs in spite of the fact that the more people there are in a team, the less hard individuals work. This study shows that the effort individuals put into team work decreases steadily with group size. In fact, in large teams of 32 people, individual members were found to be putting in only about 80% of the person-hours (effort) of individual workers. Psychologists call this effect “social loafing”.
The same study though, suggests that despite the drop off in effort, large teams still outperform a similar sized group of individuals on complex tasks. Collaboration between individuals increases with team size, generating “collective intelligence” that far surpasses that of any one individual.
However, not all tasks are best performed by teams. When a job is simple, it is better to allocate it to an individual rather than a teams to maximise efficiency. As we have seen, individuals working alone tend to work harder than individuals working in teams, so if there is little to be gained from leveraging the collective intelligence of the group, it is better to leave a job to one person to handle.
Furthermore, although groups can produce more and better ideas than individuals working alone, even better ideas can be produced by a combination of individual and group work. As this study shows, to maximise problem solving ability, it can be better to ask all team members to work on new ideas on their own, then regroup to sort through and refine these ideas together. Repeating this process several times has been shown to be the most effective way of encouraging creativity in some contexts.