Friend or foe: The effect of implicit trustworthiness judgments in social decision-making

The human face appears to play a key role in signaling social intentions and usually people form reliable and strong impressions on the basis of someone's facial appearance. Therefore, facial signals could have a substantial influence on how people evaluate and behave towards another person in a social interaction, such as an interactive risky decision-making game. Indeed, there is a growing body of evidence that demonstrates that social behavior plays a crucial role in human decision-making. Although previous research has demonstrated that explicit social information about one's partner can influence decision-making behavior, such as knowledge about the partner's moral status, much less is known about how implicit facial social cues affect strategic decision-making. One particular social cue that may be especially important in assessing how to interact with a partner is facial trustworthiness, a rapid, implicit assessment of the likelihood that the partner will reciprocate a generous gesture. In this experiment, we tested the hypothesis that implicit processing of trustworthiness is related to the degree to which participants cooperate with previously unknown partners. Participants played a Trust Game with 79 hypothetical partners who were previously rated on subjective trustworthiness. In each game, participants made a decision about how much to trust their partner, as measured by how much money they invested with that partner, with no guarantee of return. As predicted, people invested more money in partners who were subjectively rated as more trustworthy, despite no objective relationship between these factors. Moreover, the relationship between the amount of money offered seemed to be stronger for trustworthy faces as compared to untrustworthy faces. Overall, these data indicate that the perceived trustworthiness is a strong and important social cue that influences decision-making.

[1]  M. Bar,et al.  Very first impressions. , 2006, Emotion.

[2]  Jonathan D. Cohen,et al.  The Neural Basis of Economic Decision-Making in the Ultimatum Game , 2003, Science.

[3]  Glenda M. Fisk,et al.  Is “service with a smile” enough? Authenticity of positive displays during service encounters , 2005 .

[4]  P. Ekman,et al.  Felt, false, and miserable smiles , 1982 .

[5]  D. Berry,et al.  Perceiving character in faces: the impact of age-related craniofacial changes on social perception. , 1986, Psychological bulletin.

[6]  S. Quartz,et al.  Getting to Know You: Reputation and Trust in a Two-Person Economic Exchange , 2005, Science.

[7]  Linda Mealey,et al.  Enhanced memory for faces of cheaters , 1996 .

[8]  John Orbell,et al.  Physical Attractiveness, Opportunity, and Success in Everyday Exchange1 , 1998, American Journal of Sociology.

[9]  T. Yamagishi,et al.  You can judge a book by its cover: Evidence that cheaters may look different from cooperators , 2003 .

[10]  D. Berry,et al.  Were the Physiognomists Right? , 1989 .

[11]  M. Delgado,et al.  Perceptions of moral character modulate the neural systems of reward during the trust game , 2005, Nature Neuroscience.

[12]  C. Carver,et al.  Behavioral inhibition, behavioral activation, and affective responses to impending reward and punishment: The BIS/BAS Scales , 1994 .

[13]  R. Dolan,et al.  Brain Responses to the Acquired Moral Status of Faces , 2004, Neuron.

[14]  G. Pagnoni,et al.  A Neural Basis for Social Cooperation , 2002, Neuron.

[15]  Catherine C. Eckel,et al.  Reciprocal Fairness and Social Signaling : Experiments with Limited Reputations , 1998 .

[16]  David G. Amaral,et al.  The primate amygdala and the neurobiology of social behavior: implications for understanding social anxiety , 2002, Biological Psychiatry.

[17]  Joyce E. Berg,et al.  Trust, Reciprocity, and Social History , 1995 .

[18]  J. O'Doherty,et al.  Automatic and intentional brain responses during evaluation of trustworthiness of faces , 2002, Nature Neuroscience.

[19]  Ran R. Hassin,et al.  Facing faces: studies on the cognitive aspects of physiognomy. , 2000, Journal of personality and social psychology.

[20]  Janine Willis,et al.  First Impressions , 2006, Psychological science.

[21]  J. Joireman,et al.  Where do motivational and emotional traits fit within three factor models of personality , 1999 .

[22]  Christopher Andrew,et al.  Differential neural responses to overt and covert presentations of facial expressions of fear and disgust , 2000, NeuroImage.

[23]  V. Smith,et al.  Friend-or-foe intentionality priming in an extensive form trust game , 2000 .

[24]  Catherine C. Eckel,et al.  Judging a Book by its Cover: Beauty and Expectations in the Trust Game , 2006 .

[25]  Colin Camerer.  Behavioral Game Theory , 1990 .

[26]  Catherine C. Eckel,et al.  The Value of a Smile: Game Theory with a Human Face , 2001 .

[27]  A. Buchner,et al.  No enhanced memory for faces of cheaters , 2008 .

[28]  S. Brownlow,et al.  Seeing is believing: Facial appearance, credibility, and attitude change , 1992 .

[29]  C. Frith,et al.  Interacting minds--a biological basis. , 1999, Science.

[30]  N. Kanwisher,et al.  The Fusiform Face Area: A Module in Human Extrastriate Cortex Specialized for Face Perception , 1997, The Journal of Neuroscience.

[31]  C. F. Bond,et al.  The Kernel of Truth in Judgments of Deceptiveness , 1994 .

[32]  R. Adolphs,et al.  The human amygdala in social judgment , 1998, Nature.

[33]  M. Schweitzer,et al.  The Influence of Physical Attractiveness and Gender on Ultimatum Game Decisions. , 1999, Organizational behavior and human decision processes.