A. Spagnolli et al. (Eds.): PERSUASIVE 2014, LNCS 8462, pp. 191–200, 2014. © Springer International Publishing Switzerland 2014 Investigating the Influence of Social Exclusion on Persuasion by a Virtual Agent Peter A.M. Ruijten, Jaap Ham, and Cees J.H. Midden Eindhoven University of Technology, School of Innovation Sciences, Eindhoven, Netherlands, P.O. 513 p.a.m.ruijten@tue.nl Abstract. Persuasive agents may function as a tool to induce changes in human behavior. Research has shown that human-likeness of such agents influences their effectiveness. Besides characteristics of the agent, other characteristics may also have strong influences on persuasive agents’ effectiveness. One such characteristic is social exclusion. When people feel socially excluded, they are more sensitive to social influence. In two studies, we investigated this effect in a human-agent interaction. Results show stronger behavior changes for socially exclusion compared to social inclusion. This effect seems stronger for females than for males. Keywords: Social exclusion, Social influence, Virtual agent. 1 Introduction Artificial agents are becoming more prevalent in our society. Most of those artificial agents have in common that they are designed to make our life more comfortable. Another possible employment of such agents is to help us being more sustainable and reduce our carbon footprint. In this context artificial agents are used to persuade con- sumers into changing their behavior. Persuasive artificial agents may function as an effective tool to induce changes in human behavior [1]. As such, a persuasive artificial agent may function as an effective tool to induce changes in human behavior [1]. It has been argued that anthropomorphism is a key concept in the effectiveness of social feedback from artificial agents [2]. Research has shown that anthropomorphic artificial agents are evaluated more positively [3], and are experienced as more socially present [4] compared to non-anthropomorphic artifi- cial agents. However the effectiveness of artificial agents is not only dependent on agent characteristics, but also on human characteristics [5]. The tendency to anthro- pomorphize agents or other objects can differ between individuals. Epley and col- leagues’ theoretical framework [5] described sociality motivation (the desire for social contact and affiliation) as one of the major factors that cause people to have a higher tendency to anthropomorphize non-human objects. Furthermore, the tendency to anthropomorphize objects or artificial agents is thus larger for people who are chronically lonely compared to those who are chronically connected with others