Interpersonal trust can be understood as “a risky choice of making oneself dependent on the actions of another in a situation of uncertainty, based upon some expectation of whether the other will act in a benevolent fashion despite an opportunity to betray” (Thielmann and Hilbig 2015, p. 251).
Whether among romantic partners, friends, colleagues, or even strangers, trust plays a pivotal role for all kinds of social interactions and interpersonal relationships. For example, imagine confiding a personal secret to a friend, handing over your keys to your neighbor for the time you are on holidays, or asking a stranger in the train to keep an eye on your luggage while you visit the restrooms: All these instances are basically a matter of trust. In other words, in all these situations, there is uncertainty about how the trusted party will behave and, in consequence, a risk of experiencing some disutility due to being betrayed. Trusting thus means to accept individual vulnerability in such situations, arguably based on the expectation that the trusted party will behave in a trustworthy manner (see Definition). As an experimental paradigm modeling the basic characteristics of trust situations in a controlled setting, the trust game (Berg et al. 1995) has become a prominent and convenient approach for the study of trust behavior. In this game, two players both receive a certain monetary endowment, say $10. Player 1, the trustor, can freely decide whether to transfer any amount of this endowment to Player 2, the trustee. The amount the trustor transfers is multiplied by a constant larger than 1 (typically tripled) and added to the trustee’s endowment. In turn, the trustee can decide how much of the (inflated) transfer to return to the trustor. By implication, the amount the trustor transfers mirrors her level of trust – entrusting some amount to the trustee implies taking the risk of being exploited – whereas the amount the trustee returns mirrors her level of trustworthiness.
In general, trust behavior is considered to be a result of both, features of the specific trust situation and a trustor’s personality characteristics. That is, on the one hand, individuals typically condition their trust behavior on situational influences (e.g., the trustee’s appearance or reputation), thus showing certain intraindividual variability in trust behavior across situations. On the other hand, however, individuals also show noteworthy consistency in their average tendency to trust others, thus suggesting certain intraindividual stability in trust behavior across situations (Fleeson and Leicht 2006). This stability, in turn, implies a person-specific inclination to trust others and an influence of individuals’ personality traits on trust behavior. These person-specific determinants of trust behavior are the focus of the current entry. More specifically, the entry concentrates on trust among strangers as the “most basic” type of trust that builds the foundation for all kinds of trusting relationships (see Thielmann and Hilbig 2015, for a thorough discussion).
Trust from a Personality Perspective
To account for interindividual variation in trust behavior, prior research has mainly considered a specific trait dimension termed trust propensity. In particular, trust propensity denotes an individual’s “general willingness to trust others” (Mayer et al. 1995, p. 715) or, alternatively, “one’s personal tendency to believe in others’ trustworthiness” (Das and Teng 2004, p. 109). As these different definitions demonstrate, the conceptualization of trust propensity suffers some fuzziness – denoting a general behavioral intention versus a generalized expectation in others’ goodwill. As a consequence, there is heterogeneity in corresponding measures of trust propensity and, more problematically, also in empirical evidence linking trust propensity to trust behavior. That is, a positive link between trust propensity and trust behavior could only be corroborated for some trust propensity scales, but not for others (e.g., Ben-Ner and Halldorsson 2010), implying weak evidence overall.
Besides conceptual and measurement-related issues, another limitation of the concept of trust propensity refers to the underlying assumption that a single trait dimension can sufficiently account for interindividual differences in a multifaceted and complex behavior such as trust. This seems oversimplified a priori. As defined above, trust involves several components, namely, uncertainty and risk (i.e., the trustor will never have conclusive knowledge about the trustee’s trustworthiness and thus potentially experience a loss), expectations (i.e., the trustor has to infer the trustee’s trustworthiness given the inherent uncertainty of the trust situation), and vulnerability (i.e., the trustor has to accept potential disutility due to betrayal). Based on these components, Thielmann and Hilbig (2015) distilled three determinants underlying trust which are assumed to drive trust behavior, particularly among strangers, independent of – or in some interaction with – each other and which are further rooted in different personality traits: (i) risk aversion and loss aversion, (ii) trustworthiness expectations, and (iii) betrayal sensitivity. In particular, risk aversion and loss aversion (i) denote individuals’ general attitudes toward uncertainty and potential losses, respectively, and imply that personality aspects such as trait anxiety and fear explain individual variation in trust behavior. Furthermore, an influence of trustworthiness expectations (ii) suggests that, from a personality perspective, individuals’ own trustworthiness (i.e., their trait fairness and honesty) matters for trust to occur – given that individuals seem to use their own trustworthiness to infer others’ trustworthiness, a phenomenon called social projection (e.g., Krueger et al. 2012). Finally, betrayal sensitivity (iii) rests on the notion that individuals differ in the extent to which they are betrayal averse (e.g., Bohnet and Zeckhauser 2004) and thus attribute a greater severity to losses resulting from human selfishness compared to formally equivalent losses resulting from nature (i.e., bad luck). By definition, betrayal sensitivity is a question of individuals’ tolerance and forgiveness in reaction to others’ transgressions, thus implying that trait forgiveness should be another personality characteristic accounting for individual variation in trust behavior.
Fortunately, all these three specific trait determinants (i.e., anxiety/fear, trustworthiness, and forgiveness) are captured in well-established models of basic personality structure. Most prominently, in the Big Five framework (see corresponding entry in this book for details and references), trait anxiety/fear is part of the Neuroticism factor, trait trustworthiness is integrated in the Big Five Agreeableness factor, and forgiveness seems to be a matter of both, low Neuroticism and high Agreeableness (see Thielmann and Hilbig 2015, for a summary of corresponding evidence). Also, note that Big Five Agreeableness also specifically includes a trust facet subsuming an individual’s tendency to believe in others’ benevolent intentions (akin to trust propensity, as defined by Das and Teng 2004; see above). In sum, as implied by the determinants of trust, the Big Five will account for individual variation in trust behavior through Neuroticism and Agreeableness, arguably showing a negative link for the former and a positive link for the latter. Corresponding to this prediction, evidence directly supports a positive influence of Big Five Agreeableness on trust in the trust game and a (albeit weak) trend for a negative influence of Neuroticism (Zhao and Smillie 2015). In general, however, evidence on the relation between the Big Five factors and trust behavior is scarce, thus emphasizing the necessity of future research.
Beyond the Big Five, the distilled determinants underlying trust can also be integrated with the more recently proposed HEXACO model of personality structure (e.g., Ashton et al. 2014), a slightly extended and revised version of the Big Five framework. In the HEXACO model, trait anxiety/fear is captured in Emotionality – roughly speaking, the counterpart of Big Five Neuroticism. Trustworthiness, in turn, is integrated in the newly proposed sixth basic personality factor, Honesty-Humility, which covers aspects of active cooperation (i.e., fairness and greed avoidance). Finally, trait forgiveness is specifically covered by HEXACO Agreeableness – an adapted variant of Big Five Agreeableness that covers reactive cooperation (i.e., tolerance and forgiveness). So, from a theoretical perspective (Thielmann and Hilbig 2015), the HEXACO model will account for trust behavior based on three basic trait dimensions: Emotionality, Honesty-Humility, and Agreeableness. Compared to the Big Five, the HEXACO model thus allows for a more fine-grained analysis of the trait basis underlying trust because each of the three trust determinants is captured in a single basic trait factor. For Honesty-Humility, research already supports the proposed association with trustworthiness expectations as a path of social projection based on individuals’ own trustworthiness (Thielmann and Hilbig 2014). However, for the remaining determinants, empirical evidence on the relation between the HEXACO traits and trust is missing so far, thus calling for corresponding future research.
Interpersonal trust is a key aspect of our daily social life. Implying a personality basis underlying trust behavior beyond situational influences, research shows that individuals exhibit certain stability in their tendency to trust others across trust situations. Given the complex nature of trust behavior involving different components (i.e., uncertainty/risk, expectations, vulnerability), it is however oversimplified to assume that one specific trait (such as trust propensity) can sufficiently account for interindividual variation in trust behavior. Rather, the current state of research (Thielmann and Hilbig 2015) suggests that trust behavior should be determined by different personality traits as captured in well-established models of basic personality structure (e.g., Big Five and HEXACO model). Correspondingly, research supports the proposed relations of trust behavior with Big Five Agreeableness and Neuroticism as well as of trustworthiness expectations with HEXACO Honesty-Humility. Nonetheless, evidence on the links between trust behavior and basic personality traits is still mainly theoretical in nature, thus emphasizing the need for future research providing corresponding empirical evidence.
- Krueger, J. I., DiDonato, T. E., & Freestone, D. (2012). Social projection can solve social dilemmas. Psychological Inquiry, 23(1), 1–27.Google Scholar
- Mayer, R. C., Davis, J. H., & Schoorman, F. D. (1995). An integrative model of organizational trust. The Academy of Management Review, 20(3), 709–734. doi:10.2307/258792.Google Scholar