Accumulation and destruction of the trust ? : Popperian inspiration plan[Accumulation et destruction de la confiance ? : un schéma d'inspiration poppérienne]

When, following other social sciences, economists address the mechanism of trust, they typically focus on the search of a justification or a foundation for trusting, the implicit starting point of the process they have in mind being zero trust, or distrust. By contrast, the present paper, inspired by the philosophy of Popper, suggests, as a starting point for trust, an individual decision associated with what Popper calls a conjecture - that is, a kind of theory - on how the individual (potentially) trusted "functions". The conjecture requires no justification but only the test of its implications. In turn, the decision to trust or to distrust does not reflect in a mechanical or passive way the extent to which the conjecture is corroborated, a fortiori any kind of degree of belief or of probability. In the spirit of Popperian asymmetry, the paper explains decreasing trust essentially in epistemological terms but increasing trust both in epistemological terms and by the building-up of knowledge capital specific to the relation.