Group-level cognitive states are widely observed in human social systems, but their discussion is often ruled out a priori in quantitative approaches. In this paper, we show how reference to the irreducible mental states and psychological dynamics of a group is necessary to make sense of large scale social phenomena. We introduce the problem of mental boundaries by reference to a classic problem in the evolution of cooperation. We then provide an explicit quantitative example drawn from ongoing work on cooperation and conflict among Wikipedia editors. We show the limitations of methodological individualism, and the substantial benefits that come from being able to refer to collective intentions and attributions of cognitive states of the form "what the group believes" and "what the group values".
Group Minds and the Case of Wikipedia