Final answer:
The central feature of initiating small conciliatory acts for a reciprocal response is known as Reciprocal Altruism. This concept relies on the expectation of mutual benefit and requires repeated interactions to ensure the continuation of support and cooperation.
Step-by-step explanation:
Initiating one or more small conciliatory acts which open the door to a reciprocal response is a central feature of Reciprocal Altruism. This concept is rooted in the behavior where the "giving" actions of an individual are based on the expectation of a future return of the favor, forming a mutual benefit scenario. Unlike generalized reciprocity, which is based on the egalitarian sharing without the expectation of something in return, reciprocal altruism requires repeated encounters and a mechanism for punishing those who do not reciprocate, also known as 'cheaters'. This is observed in both human societies and among animal species, where individuals may help others with the anticipation of being helped in the future, creating a network of social support reinforced by the principle of reciprocity.