Connectivity –particularly as networks expand to be large and even global in scale - greatly increases prospects of cooperation. In this chapter we first discuss the concept of connectivity and its relationship to cooperation as it has been explored across disciplines. The discussion focuses on the two main questions pursued in connectivity research; how do cooperative connections emerge, and which connections are most efficient when promoting cooperation? Much of the initial research to be discussed is laboratory based, allowing for strict controlled conditions to test the effect of network density and structure on performance. The final set of connectivity research reviewed we discuss is a set of field experiments that allow for greater external validity, yet also allowing for replication of the key results linking connectivity among target populations and cooperation.
In the second half of this chapter we present results from a six country study of the global connections of 1195 participants and their propensities to cooperate with one another. In this research we push the limits of the scale of connectivity, but also alter elements of network density and structure typically found in prior research. Nonetheless, the results demonstrate that as global connectivity increases, cooperation increases as well.