The Effect Of Face Gender And Facial Dimorphism On Trust Decision-making And The Psychological Mechanism

"Trust others or don't trust others?" It is a kind of behavior choice often faced in social interaction,which directly affects individual social life.Trust game tasks are often used to measure social trust behavior and trust cognition.Trust decision is a decision in the trust game,that is,the decision made by investors between trust(giving all the money to the other party)and distrust(keeping all the money).Based on the gender role theory,the social category information(such as gender)contained in faces can affect people's trust.Based on the content model of face social perception,the physiological characteristics of face(such as face dimorphism)can influence people's judgment of face trustworthiness.However,when face social category information and face physiological characteristics coexist,how the two types of face cues affect people's trust remains to be discussed.In this study,behavioral experiments and electrophysiological methods were used to explore the influence of face gender and face dimorphism on trust decision-making and its psychological mechanism.This paper contains three studies with a total of eight experiments:Study 1 consisted of two behavioral experiments and one ERPs experiment: preexperiment a used a behavioral experimental approach to screen gender face materials with different face gender discriminations.Experiment 1 used the behavioral experimental method to examine the effect of face gender on trust decisions,and also manipulated the stability of face gender discrimination to measure the effect of face gender on trust decisions.Experiment 2 used an event-related potential technique to examine the effect of face gender on trust decisions,recording subjects' neural responses when viewing faces(male faces and female faces)and making decisions at high and low face gender discrimination levels.The results of Experiment 1 found that people gave more trust investment to female faces than to male faces,and the phenomenon was consistently observed even when face gender discrimination was reduced.Behavioral results from Experiment 2 found that people gave more trust investment to female faces than to male faces;results from ERPs found that viewing faces with low face gender discrimination induced a more negative N170 wave amplitude and viewing female faces induced a greater P2 wave amplitude than viewing male faces,but no significant differences in the components of ERPs were found when making decisions.Study 2 consisted of two behavioral experiments and one ERPs experiment: preexperiment b used a behavioral experimental method to screen four types of face materials: feminized female faces,feminized male faces,masculine female faces,and masculine male faces.Experiment 3 used behavioral experimental method to examine the effect of face gender and face dimorphism on trust decision,and also manipulated the stability of gender stereotype to measure the effect of face gender and face dimorphism on trust decision.Experiment 4 examined the effect of face gender and face dimorphism on trust decision making using an event-related potential technique,recording subjects' neural responses when viewing faces(feminized female faces,feminized male faces,masculinized female faces,and masculinized male faces)and when making decisions.The results of Experiment 3 found that individuals invested more trust in feminized female faces than in feminized male faces,and as much trust in masculinized female faces as in masculinized male faces;individual gender stereotypes failed to influence the phenomenon.The behavioral results of Experiment 4 again validated the behavioral results of Experiment 3;the ERPs results of Experiment 4found that viewing feminized female faces induced greater P2 and LPC amplitudes than viewing feminized male faces,but viewing masculinized female faces did not induce significantly different P2 and LPC amplitudes than viewing masculinized male faces,and no significant differences were found in the components of ERPs at decision making significant differences.Study 3 contains two behavioral experiments to explore the psychological mechanism of face gender and face dimorphism influencing trust decision-making.Experiment 5 used to investigate the mediating role of face characteristics in the influence of face gender and face dimorphism on trust decision-making.Experiment 6examines the mediating role of personality trait labels and face traits in the influence of face gender and face dimorphism on trust decision-making.The results of Experiment5 found that the dominance of faces played a mediating role in the influence of face gender and face dimorphism on trust decision-making.The results of Experiment 6found that face gender and face dimorphism can affect trust decision-making by affecting negative male personality trait labels,and it can also affect trust decisionmaking by affecting the dominance of faces.The above results show that people trust female faces more than male faces.Feminine face features magnify the trust differences of different gender faces,while masculine face features narrow the trust differences of different gender faces;People put more attention resources into the processing of trusted faces.In addition,bottomup data-driven processing(face traits)and top-down concept-driven processing(personality trait labels)are the potential psychological mechanisms that face gender and face dimorphism influence trust decision-making,and the evaluation of face traits determines trust decision-making.Future research can compare a variety of ways to operate face dimorphism and a variety of ways to measure trust decision,and further verify the stability and scope of application of the research results.