Are non-verbal facial cues of altruism cross-culturally readable?

Effects of sex and sex-related facial traits on trust and trustworthiness: An experimental study

The ability to trust others, including strangers, is a prerequisite for human cooperation. Economically it is not rational to trust strangers, as trust can be easily exploited. Still, generally, the level of trust toward strangers is relatively high. Trust is closely related to trustworthiness: when trusting others, one expects them to reciprocate. Some individuals elicit more trust than others. Apparently, humans use subtle cues for judging the trustworthiness of their interaction partners. Here, we report on an experiment that investigates trust and trustworthiness in a population of 176 mainly Dutch students. The aims of our study were: (1) to investigate how the sex of interaction partners and their facial appearance (femininity/masculinity) affect the degree of trust and trustworthiness, compared to fully anonymous conditions; (2) to test whether individuals who elicit trust in their interaction partners are trustworthy themselves. Each subject of our experiment played five one-shot Trust Games: one with an anonymous interaction partner, and four "personalized" games after seeing a 20 s silent video of their interaction partner (twice same-sex, and twice opposite-sex). The degree of facial sexual dimorphism was investigated with geometric morphometrics based on full-face photographs. Our results revealed that, despite the already high level of trust in the anonymous setting, the personalization of interactions had a clear effect on behavior. Females elicited more trust in partners of both sexes. Interestingly, females with more feminine faces elicited less trust in both male and female partners, while males with more masculine facial shape were more trusted by females, but less trusted by males. Neither sex nor facial femininity/masculinity predicted trustworthiness. Our results demonstrate that (1) sex and sex-related facial traits of interaction partners have a clear effect on eliciting trust in strangers. However, (2) these cues are not reliable predictors of actual trustworthiness.

Emotion Perception Rules Abide by Cultural Display Rules

The current study compared emotion perception in two cultures where display rules for emotion expression deviate. In Experiment 1, participants from America and Korea played a repeated prisoner's dilemma game with a counterpart, who was, in actuality, a programmed defector. Emotion expressions were exchanged via emoticons at the end of every round. After winning more points by defecting, the counterpart sent either a matching emoticon (a joyful face) or a mismatching emoticon (a regretful face). The results showed that Americans in the matching condition were more likely to defect, or to punish, compared to those in the mismatching condition, suggesting that more weight was given to their counterpart's joyful expression. This difference was smaller for Koreans, suggesting a higher disregard for the outward expression. In a second, supplementary experiment, we found that Korean participants were more likely to cooperate in the mismatching or regretful condition, when they thought their counterpart was a Westerner. Overall, our data suggest that emotion perception rules abide by the display rules of one's culture but are also influenced by the counterpart's culture.

Predicting Trustworthiness Across Cultures: An Experiment

We contribute to the ongoing debate in the psychological literature on the role of “thin slices” of observable information in predicting others' social behavior, and its generalizability to cross-cultural interactions. We experimentally assess the degree to which subjects, drawn from culturally different populations (France and Japan), are able to predict strangers' trustworthiness based on a set of visual stimuli (mugshot pictures, neutral videos, loaded videos, all recorded in an additional French sample) under varying cultural distance to the target agent in the recording. Our main finding is that cultural distance is not detrimental for predicting trustworthiness in strangers, but that it may affect the perception of different components of communication in social interactions.

How to Detect Altruists: Experiments Using a Zero-Acquaintance Video Presentation Paradigm

In this study, we investigated the cognitive processes and nonverbal cues used to detect altruism in three experiments based on a zero-acquaintance video presentation paradigm. Cognitive mechanisms of altruism detection are thought to have evolved in humans to prevent subtle cheating. Several studies have demonstrated that people can correctly estimate levels of altruism in others. In this study, we asked participants to distinguish altruists from non-altruists in video clips using the Faith game. Participants decided whether they could trust allocation of money to the targets who were videotaped while talking to the experimenter. In our first experiment, we asked the participants to play the Faith game under cognitive load. The accuracy of altruism detection was not reduced when participants simultaneously performed a cognitive task, suggesting that altruist detection is rapid and effortless. In the second experiment, we investigated the effects of affective status on the accuracy of altruism detection. Compared with participants in a positive mood, those in a negative mood were more hesitant to trust videotaped targets. However, the accuracy with which altruism levels were detected did not change when we manipulated participants’ moods. In the third experiment, we investigated the facial cues by which participants detected altruists. Participants could not detect altruists when the upper half of the target’s face was hidden, suggesting that judgment cues exist around the eyes. We also conducted a meta-analysis on the effect size in each experimental condition to verify the robustness of altruism detection ability.

Does he sound cooperative? Acoustic correlates of cooperativeness

The sound of the voice has several acoustic features that influence the perception of how cooperative the speaker is. It remains unknown, however, whether these acoustic features are associated with actual cooperative behaviour. This issue is crucial to disentangle whether inferences of traits from voices are based on stereotypes, or facilitate the detection of cooperative partners. The latter is likely due to the pleiotropic effect that testosterone has on both cooperative behaviours and acoustic features. In the present study, we quantified the cooperativeness of native French-speaking men in a one-shot public good game. We also measured mean fundamental frequency, pitch variations, roughness, and breathiness from spontaneous speech recordings of the same men and collected saliva samples to measure their testosterone levels. Our results showed that men with lower-pitched voices and greater pitch variations were more cooperative. However, testosterone did not influence cooperative behaviours or acoustic features. Our finding provides the first evidence of the acoustic correlates of cooperative behaviour. When considered in combination with the literature on the detection of cooperativeness from faces, the results imply that assessment of cooperative behaviour would be improved by simultaneous consideration of visual and auditory cues.