While the concept of trust has been addressed by many scholarly disciplines, its definition remains the source of considerable conflict. Indeed, according to Russell Hardin, "[t]here is no Platonically essential notion of trust." Nevertheless, most definitions of trust share several characteristics.

Professor Karen Jones describes four characteristics virtually essential to any account of trust: (1) trust involves risk; (2) those who trust are willing to forgo an immediate accounting of how or even whether the one trusted has responded to trust with trustworthiness, and to allow the one trusted some discretion as to how to fulfill that trust; (3) trust enhances the effectiveness of agency; and (4) trust and distrust are self-confirming, distrust even more strongly so than trust.

In the context of the schema, the establishment of trust is effectively the starting point for cooperative behavior.

References

Russell Hardin, Trust and Trustworthiness xx (2002).
Karen Jones, "Trust," in Routledge Encyclopedia of Philosophy (1998), available at http://www.rep.routledge.com/article/L107SECT1.