Rationality Personal and Social

Being rational in complete social isolation seems veritably useless. One may remain credible religious if stuck for life on an otherwise uninhabited island. But rationality seems to concern how one behaves in a social context, not about merely what, say, one believes about the universe. A number of writers have looked to the seemingly, purely, inherent social context of rationality, notably Weber and Habermas. Their explicitly social concern adds further useful angles and insights into rationality. Can a society be considered an agent, and if so, can it act rationally? This question helps round out the argument of what rationality consists in.