The Role of Intuition in Interpersonal Trustworthiness and Vulnerability Assessments

The basic discrimination of friend and foe was likely one of the earliest interpersonal judgments to evolve (e.g., O’Sullivan, 2003). Such decisions had to occur rapidly, perhaps intuitively, to inform the best course of action for survival. Intuitive interpersonal decisions appear to be based largely on the face, which acts as the display board on which emotions and intentions are communicated, and is scrutinized during social interactions and encounters with strangers (Martelli et al., 2005). Inferences of trustworthiness, based on a stranger’s face, occur within 38ms and while confidence in judgment accuracy increases with more lengthy exposure to a face, assessments remain virtually unchanged (Bar et al., 2006; Willis & Todorov, 2006). The instantaneous and enduring nature of these assessments can color subsequent decision-making (Porter & ten Brinke, 2008a). However, evidence does not suggest that these automatic judgments are highly accurate. The evolutionary development of deception and emotional concealment has complicated such assessments so that observers can only discriminate the faces of humanitarians vs. violent criminals slightly above chance (Porter et al., 2008). Despite the apparent shortcomings of trustworthiness assessments based on still facial images, it appears that very short observations of a stranger’s behaviour can inform rapid interpersonal decisions by both human predators and prey. Observing only five seconds of a stranger’s behaviour can result in reasonably reliable and valid first impressions of a psychopathic personality, characterized by callousness, manipulation and persistent antisocial behaviour (Fowler, Lilienfeld & Patrick, 2009). Psychopathic individuals, however, are not without intuitive countermeasures. Psychopaths have mastered the art of manipulation to overcome intuitive impressions of their dangerousness, creating willing victims and convincing decision-makers to be lenient in sentencing and parole hearings (Hakkanen-Nyholm & Hare, 2009; Porter, ten Brinke & Wilson, Interpersonal intuition 3 2009). Further, psychopathic personality traits appear to be associated with an enhanced ability to assess stranger vulnerability and maintain superior recollection of such potential victims (Book, Quinsey & Langford, 2007; Wilson, Demetrioff & Porter, 2008). Thus, while the evolutionary development of deception has likely diminished the accuracy of certain interpersonal decisions, brief observations of a stranger’s behaviour can inform reasonably accurate insights into their dangerousness and vulnerability. Interpersonal intuition 4 Friend or Foe? The Role of Intuition in Interpersonal Trustworthiness and Vulnerability Assessments Upon meeting an individual for the first time, we rapidly come to conclusions about that person’s state and trait characteristics (Martelli et al., 2005). With little additional information available, we have come to rely on intuitive assessments and quick decision rules, or heuristics, to inform the course of our subsequent interaction. These decisions, based on physical features, non-verbal behaviour, or “thin slices” of social interaction, can sometimes be accurate but can also be unreliable, leading subsequent decision-making astray (Porter & ten Brinke, 2008a). Despite the questionable validity of these split-second subconscious assessments, society in general appears to value intuition. In the courtroom, for example, “the ring of truth” is a commonly cited aspect of credibility assessments performed by Canadian judges (see R. v. Mervyn, 2003; R v. Roble, 2004; R. v. S. (R.D.), 1997). In R. v. Lifchus (1997), Justice Cory noted: “it may be that the juror is unable to point to the precise aspect of the witness's demeanour which was found to be suspicious.A juror should not be made to feel that the overall, perhaps intangible, effect of a witness's demeanour cannot be taken into consideration in the assessment of credibility. ” However, there is no evidence that the use of intuition is valid in evaluating credibility. In fact, contrary to Justice Cory’s suggestion, Porter et al. (2000) found that a selfreported reliance on intuition and accuracy in detecting deception were inversely related. Continued adherence to this initial assessment can lead to a non-critical, “tunnel vision” assimilation of information and create an incorrect but highly-confident decision maker, potentially leading to wrongful convictions (Porter, Gustaw & ten Brinke, 2009). This is not to say, however, that intuitive interpersonal assessments have no value. It is noteworthy that some inferences based solely on a glimpse of the face have evolved to be valid. Interpersonal intuition 5 The identification of genuine emotional expressions (especially anger) is rapid and highly accurate (Williams & Mattingley, 2006). Additionally, inferences that may inform friend v. foe and fight v. flight decisions, such as a stranger’s level of extraversion, masculinity and dangerousness appear to be correlated with objective measures of these traits (Borkenau & Leibler, 1992; Fowler, Lilienfeld & Patrick, 2009; Yeagley, Morling & Nelson, 2007). Further suggesting an evolutionary basis for some intuitive assessments, women are able to accurately rate men’s interest in infants based only on photographs of the men’s faces (Roney et al., 2006). The goal of this chapter is to explore interpersonal intuition of human predator and prey, and consider the validity of each, in an evolutionary context. Trust Games: Exploring the Validity of Intuitive Trustworthiness Assessments The basic discrimination of friend and foe likely was one of the earliest interpersonal judgments to evolve and had to occur rapidly. In a demonstration of the expediency of these assessments, Willis and Todorov (2006) had participants view images of a face for 100ms, 500ms, one second, or unlimited time, and evaluate trustworthiness and other traits (e.g., likeability, aggressiveness). While confidence in judgment accuracy increased with increased time, the judgments remained virtually unchanged from the initial brief exposure. 100ms judgments had the greatest impact for the trait of trustworthiness, indicating their instantaneous and enduring nature. Further examinations have revealed that trustworthiness can be reliably determined after as little as 38ms of exposure to a stranger’s face (Bar, Neta & Linz, 2006). Recent research by Todorov and colleagues has attempted to determine what information is gleaned from the face to form decisions of trustworthiness using data-driven models. A two dimensional model, combining assessments of facial valence and dominance can account for over 80% of variance in trustworthiness ratings (Oosterhof & Todorov, 2008). Impressions of Interpersonal intuition 6 valence, or emotion, are important signals of behavioural intentions and can assist with approach or avoidance decisions. This dimension accounted for 63.3% of the variance in trustworthiness ratings. Additionally, impressions of dominance, or masculinity/maturity, can signal one’s physical strength and ability to do harm, informing the choice between fight and flight. Impressions of dominance accounted for an additional 18.3% of variance in trustworthiness assessments. In sum, this model suggests that intuitive impressions of (un)trustworthiness combine evaluations of behavioural intention, based on emotional expression, with notions of physical strength that indicate the individual’s ability to inflict the harm that his/her angry facial expression predicts. Despite the expediency, reliability and seemingly rational decision-making process involved in trustworthiness assessments, these decisions are not necessarily accurate. One possibility is that this evaluation process evolved to do the job effectively. That is, as Willis and Todorov (2006) appear to assume, perhaps these automatic judgments of a stranger’s trustworthiness based on his/her face are accurate. However, this assumption is unfounded since the dispositional features of the target faces presented were unknown. More recently, Porter et al. (2008) asked participants to rate the trustworthiness of two groups of stranger faces Most Wanted criminals and comparatively upstanding Nobel Peace Prize winners. Participants were only able to discriminate group membership slightly above the level of chance. Similarly, Bond et al. (1994) found that appearance-based impressions of honesty accounted for only a “kernel of truth” (4% of the variance) in the individual’s actual willingness to engage in deception and Zebrowitz, Voinescu and Collins (1996) found no relation between real and perceived honesty of men and women based on photographs taken across the lifespan. Thus, while this two Interpersonal intuition 7 dimensional decision-making process may have evolved as a sound strategy for our ancestors, it no longer results in particularly accurate determinations of honesty. Faltering accuracy of trustworthiness impressions may be tied in part to the evolutionary development of emotional deceit. Liars frequently facilitate their deceit by altering their expressions through simulating (expressing an unfelt emotion), masking (replacing a felt expression with a false one), or neutralizing (inhibiting a true emotion by appearing neutral) an emotion (Ekman & Friesen, 1975). In a detailed examination of the what the face reveals during emotional deceit, Porter and ten Brinke (2008b) had participants view powerful emotional images, responding with a genuine or convincing but false expression while being judged by a naïve observer. The 697 videotaped expressions then were analyzed (each 1/30 sec frame for more than 100,000 frames) by coders blind to expression veracity. While no one was able to falsify emotions without leakage of their true feelings on at least one occasion, participants were often successful deceivers. Involuntary expressions were subtle; rarely expressed across the entire face