People tend to punish individuals who cause harm to others, and such punishment behaviors are particularly prominent in intergroup conflicts. Outgroup punishment behavior is an important cause of aggravated group conflict, and an in-depth study of its psychological and neural mechanisms is beneficial to understanding and eliminating intergroup conflict and promoting a harmonious society. Previous studies have found that outgroup punishment behavior exists in multiple cultural contexts, but how individuals' cultural traits influence their punishment behavior toward outgroups and the underlying neural mechanisms remained unclear.

Past research has reached inconsistent conclusions, for example, some studies have found that people in collectivist cultures are more likely to attack outgroup members, but others have found that people in collectivist cultures express diminished prejudice toward outgroups, suggesting that the cultural influence on outgroup aggression may be complex.

To address this issue, Dr. ZHOU Yuqing from Dr. KONG Yazhuo's research group at the Institute of Psychology, Chinese Academy of Sciences, conducted a study in collaboration with Dr. Shihui Han from the School of Psychological and Cognitive Sciences, Peking University. First, by collecting behavioral data in China (N=2297), the researchers found that one of the important dimensions of cultural traits, "interdependent self-construal," could be further divided into two sub-dimensions, representing the relative focus on group collectives (Esteem for Group, EG) and on harmonious relationship (Relational interdependence, RI), respectively. More importantly, the researchers found that these two sub-dimensions predict outgroup punishment behavior in opposite directions. Specifically, individuals who scored higher on the Esteem for Group dimension showed higher levels of aggressive behavior toward outgroups during intergroup conflict; conversely, individuals who scores higher on the Relational interdependence dimension were less inclined to punish outgroups during intergroup conflict (Figure 1).

 Figure 1. Associations between EG/RI and race-related punishment decisions. Image by Dr. ZHOU Yuqing.

Next, the researchers collected EEG data from people viewing painful and neutral faces of Asians and Whites in China (N=676) in order to further reveal the underlying neural mechanisms. The researchers first applied Representational similarity analysis (RSA) to the EEG data to separate the subjects' neural representations of race, pain, and gender information about the faces. The researchers further found that two sub-dimensions of the interdependent self-construals could be associated with race-related representations of faces in opposite directions. Specifically, individuals who scored higher on the Esteem for Group dimension were more sensitive to the racial attributes of faces; while individuals who were more focused on interpersonal harmony had diminished neural representations of race (Figure 2).

Figure 2. Associations between EG/RI and race-related neural representation.Image by Dr. ZHOU Yuqing.

Finally, the researchers found that individuals' neural representations of race could further mediate the relationship between sub-dimensions of the interdependent self-construal and outgroup punishment, constructing a mediation model between cultural traits, brain activity and intergroup behavior (Figure 3).

Figure 3. The mediation model of cultural traits, brain activity and intergroup behavior. Image by Dr. ZHOU Yuqing.

This study disentangled the two sub-dimensions of the interdependent self-construals by collecting and analyzing behavioral as well as EEG data, elucidated the complex relationship between the interdependent self-construal and outgroup aggression, and revealed the underlying neural mechanisms. This study helps to improve the understanding of the relationships between cultural traits and intergroup behavior, and provides a theoretical basis for the design of future intervening approach to reduce intergroup conflict.

This research was supported by the National Natural Science Foundation of China (32230043). The first author is Dr. Yuqing Zhou. Dr. Yuqing Zhou and Dr. Shihui Han are the co-corresponding authors of this paper. The research results have been published online in Cerebral Cortex on May 4th, 2023.

LIU Chen
Institute of Psychology Chinese Academy of Sciences
Beijing 100101, China.
E-mail: liuc@psych.ac.cn