Individuals experience a redundancy gain when they respond faster to two signals than one. This benefit can derive from statistical facilitation of independent decisions (Raab 1962) or from the co-activation of signals before a decision (Miller, 1982). Here we applied these tests to the redundancy gain that occurs when pairs of participants work together to detect targets. We also compared gains when each partner was responsible for one of two targets versus a different spatial region. The results showed pairs were more efficient than individuals, and that this gain was greater when the task was divided by target identity versus by space. We also found that the collaborative redundancy gain could be characterized as co-activation, meaning that the benefit of collaboration exceeded that predicted by statistical facilitation. These results serve as a proof of concept that models developed to understand information processing in individuals can help characterize collaborative performances.