Final answer:
The theory that religion encourages prosocial behavior assumes that such behavior is beneficial for the religious group and society, reinforcing social norms and fostering cohesion.
Step-by-step explanation:
The theory that religion encourages prosocial behavior assumes that such behavior is inherently valued and provides benefits to the society or group. To accept this theory as plausible, one must assume that religion plays a functional role in society by promoting cooperation and prosocial behavior among its members. These prosocial behaviors include acts of kindness, fairness, and cooperation, which can strengthen group bonds and facilitate social order.
This assumption is aligned with a functionalist perspective of religion, wherein religion is seen as an institution that contributes positively to the social system by reinforcing norms, providing meaning, and fostering social cohesion. Therefore, the assumption underlying the theory is that promoting prosocial behavior is beneficial for the religious group and for society at large.