  Individuals in groups must often choose between acting selfishly and
cooperating for the common good. The choices they make are based on their
beliefs on how they expect their actions to affect others. We show that for a
broad set of beliefs and group characteristics cooperation can appear
spontaneously in non-cooperative groups after very long periods of time. When
delays in information are unavoidable the group dynamics acquires a wide
repertoire of behaviors, ranging from opportunistic oscillations to bursty
chaos, thus excluding the possibility of sustained cooperation.
