An Experimental Study of Team Size and Performance on a Complex Task

The relationship between team size and productivity is a question of broad relevance across
economics, psychology, and management science. For complex tasks, however, where
both the potential benefits and costs of coordinated work increase with the number of workers,
neither theoretical arguments nor empirical evidence consistently favor larger vs.
smaller teams. Experimental findings, meanwhile, have relied on small groups and highly
stylized tasks, hence are hard to generalize to realistic settings. Here we narrow the gap
between real-world task complexity and experimental control, reporting results from an
online experiment in which 47 teams of size ranging from n = 1 to 32 collaborated on a realistic
crisis mapping task. We find that individuals in teams exerted lower overall effort than
independent workers, in part by allocating their effort to less demanding (and less productive)
sub-tasks; however, we also find that individuals in teams collaborated more with
increasing team size. Directly comparing these competing effects, we find that the largest
teams outperformed an equivalent number of independent workers, suggesting that gains
to collaboration dominated losses to effort. Importantly, these teams also performed comparably
to a field deployment of crisis mappers, suggesting that experiments of the type
described here can help solve practical problems as well as advancing the science of collective
intelligence.