Social context is generally thought toinfluence how humans act. Here we argue thathumans rarely accept the context as it isgiven, but rather undertake conscious actionsto make it favourable. The example chosen isfrom northern Cameroon, where nomad herdsmeninduce the sedentary farmers to trust them, bydifferent means: creation of interpersonallinks, exhibition of good behaviours byrespecting certain norms. Trust is consideredas an element of the context, necessary forthem to perform acts that present a certainrisk. An attempt was made to translate one ofthe traditional (...) behaviours into a model,implemented in an artificial society:autonomous agents would make gifts in order tocreate an image of themselves in a group. Inthe simulations, a form of reputationstratification appears in time. One notes thatan agent can build the image it wants only ifthe part of the population that wants to beinvolved in the same dynamic is big enough. Asa conclusion, we suggest that althoughindividuals try to create consciously a contextfor their living, this is not just anindividual choice, but needs a commonbackground of rules, a context enabling contextcreation. (shrink)