Grounded in a follow-up study among children who lost one or both parents to HIV in central China in the early 2000s, we conducted an event-related potentials (ERPs) experiment to explore the effect of social exclusion on trust and the corresponding neurophysiological mechanism among youth orphaned by HIV/AIDS (“AIDS orphans”). A sample of 31 AIDS orphans (26.16 ± 3.34 years old; 15 female) and 32 age and development status matched controls (25.02 ± 3.45 years old; 14 female) participated in the study. They were all assigned to play Cyberball, a virtual ball-tossing game that reliably induced social exclusion (15 orphans, 16 controls) and inclusion (16 orphans, 16 controls). Then, they played the Trust Game by taking the role of trustor with their electroencephalograms (EEGs) being recorded during the game. In the Trust Game, each participant was required to decide whether to trust their partners in over 150 trials (decision-making stage). The partner’s reciprocation strategies were pre-programmed by the experimenter (with an overall reciprocating rate of 50%). All participants were provided with post-decision feedback about the outcome of their decisions (gain or loss of game points) in each trial (outcome evaluation stage). We analyzed their behavioral responses at the decision-making stage and ERP components at the outcome evaluation stage. Behavioral results showed that the proportion of orphans choosing trust was significantly higher than the controls, and the trust ratio of the orphan exclusion (OE) group was significantly higher than that of the orphan inclusion (OI) group, control exclusion (CE) group, and control inclusion (CI) group. Furthermore, the response time of the OE group was significantly shorter than that of other groups. ERP results indicated that the amplitude of the feedback-related negativity (FRN) in the OI group was significantly more negative than that in the CI group with loss feedback, while there was no significant difference between the OE and OI groups. Similarly, the P300 amplitudes following outcome feedback were larger in the CI group than that in the OI group with gain feedback and had no significant difference between OE and OI.

Parental illness or death due to HIV/AIDS has long-term impacts on children’s social well-being, potentially challenging the children’s basic developmental needs and future. Based on the theoretical model of social well-being, the present study tested a moderated mediation model that HIV-related stigma moderated the mediating role of social trust on the relationship between perceived social support (PSS) and social well-being. A sample of 297 youths aged 20–30 years affected by parental HIV/AIDS (57.2% male), including 129 (43.40%) AIDS orphans and 168 vulnerable youths (56.60%) completed questionnaires of perceived social support, social well-being, social trust, and HIV-related stigma. IBM SPSS 25.0 was used to conduct descriptive statistics and multiple regressions. Results showed that the mean score of PSS was 61.34 (SD = 13.99), social well-being was 57.33 (SD = 10.15), social trust was 56.21 (SD = 11.55), perceived stigma was 64.44 (SD = 16.72), and enacted stigma was 21.91 (SD = 9.73) among youths affected by parental HIV/AIDS and the PSS could predict increasing social well-being via increasing social trust. Moreover, the positive influence of PSS on social trust was moderated by the enacted stigma (p = 0.03), in which the positive influence was stronger among youths affected by parental HIV/AIDS who perceived or experienced low enacted stigma than those who perceived or experienced high enacted stigma. The positive impact of social trust on social well-being was moderated by perceived stigma (p = 0.04), in which the positive impact was more significant among youths affected by parental HIV/AIDS who perceived or experienced high perceived stigma than those who perceived or experienced low perceived stigma. These findings explained how and when the PSS affected social well-being and contributed toward an understanding of the experiences and perceptions of HIV-related stigma among youths affected by parental HIV/AIDS. This understanding may inform future research and policies toward improving the social well-being of youths affected by parental HIV/AIDS. The study also highlighted the importance of strengthening interventions on social relations and reducing HIV-related stigma for them.