You might extend hospitality or act as though you trust me in order to demonstrate to me that you have faith in my morality or character or to give me an opportunity to live up to your hopes even though I may have no incentive to reciprocate your action. Alternatively, you may act according to a rule of reciprocity, doing unto others what they do unto you, even when it is not strictly in your interest to do so. Hence you may be trustworthy toward me because I am trustworthy toward you or because you may not wish to be the kind of person who acts toward another as though out of distrust that is not based on solid evidence. Such motivations are apt to lead to disappointment in many contexts, but they might be statistically justified in certain milieus. In particular, they might be justified in contexts in which there are rich possibilities of further interactions. In such contexts, however, interest is likely to conspire with your hopes in getting me to reciprocate.

XREF: Connects to game theory and iterated prisoner's dilemma logic — cooperation emerges when future interactions create stakes.

Russell Hardin, Trust and Trustworthiness, loc. 1015