NAO robot and the “endowment effect”

In this experiment, a humanoid robot (NAO), for the first time, replaces the experimenter to study the endowment effect that describes the fact that individuals prefer an object or a service that belongs to them over an equivalent object or service. The traditional methodology used to observe the endowment effect was based on a simple experimental exchange paradigm. The effect is measured along the proportion of participants reluctant to accept the exchange. This robust effect of endowment is considered in the economic literature as a serious decisional bias that seems to exist since the younger age. Two explanations have been advanced in the literature. The first explanation refers to the aversion to the loss that individuals would have as it is detailed by the prospect theory. The second explanation, the most recent one, specifies that the willingness to possess is a consequence of the evolution. We propose an additional explanation; that social rules of the individuals can explain the reluctance to exchange an object or to prefer an object already possessed over the same object that these individuals do not possess. The paradigm of the exchange would implicitly favor a response in line with politeness norms at use in Western societies. In order to account for this third explanation, the use of NAO robot allows reproducing the exchange experimental paradigm in a neutral disambiguated context where the politeness norms are not prompted by the interaction experimenters/participants. This experiment concluded to no endowment effect. This procedure reveals a new paradigm to understand the emergence of social norms at play in an interaction robot-human researching what “behaviors” programmed in NAO triggers an endowment effect and favors the emergence of politeness norms.