In this research, we varied the composition of 4-member groups. One third of the groups consisted exclusively of "locomotors," individuals predominantly oriented toward action. Another third of the groups consisted exclusively of "assessors," individuals predominantly oriented toward evaluation. The final third of the groups consisted of a mix of locomotors and assessors. We found that the groups containing only locomotors were faster than the groups containing only assessors, and the groups containing only assessors were more accurate than the groups containing only locomotors. The groups containing a mix of assessors and locomotors were as fast as the groups containing only locomotors and as accurate as the groups containing only assessors. These results echo findings at the individual level of analysis, and suggest that the testing and action components of operating systems independently contribute to performance both intra- and interpersonally.