The Effect of Agency on the Impact of Emotion Expressions on People´s Decision Making

Recent research in neuroeconomics reveals that people show different behavior and lower activation of brain regions associated with mentalizing (i.e., the inference of other´s mental states) when engaged in decision making tasks with a computer, when compared to a human. These findings are important for affective computing because they suggest people´s decision making might be influenced differently according to whether they believe the emotional expressions shown by a computer are being generated by a computer algorithm or a human. To test this, we had people engage in a social dilemma (Experiment 1) or a negotiation (Experiment 2) with virtual humans that were either agents (i.e., controlled by computers) or avatars (i.e., controlled by humans). The results show a clear agency effect: in Experiment 1, people cooperated more with virtual humans that showed facial cooperative displays (e.g., joy after mutual cooperation) rather than competitive displays (e.g., joy when the participant was exploited) but, the effect was only significant with avatars, in Experiment 2, people conceded more to an angry than a neutral virtual human but, once again, the effect was only significant with avatars.