Our objective was to determine whether or not shame types could have positive effect on prosocial behavior tendency toward a benefactor or a stranger in prosocial situations. This study found a promoting effect of public shame on prosocial behavior tendency toward strangers. Specifically, individuals in the public shame condition demonstrated a stronger willingness to help a benefactor who had ever helped the participants, rather than a stranger. Thus, the Hypothesis one was supported, which supports the functionalism of shame.
As expected, the help-seeker being a benefactor and the public shame condition were both related to higher levels of willingness to help. The finding of the positive effect of public shame on prosocial behavior tendency toward a stranger is somewhat similar to the findings by de Hooge et al. . They found that endogenous shame (i. e. related to a decision at hand) motivated prosocial behavior for ‘proselfs’ (people with a natural tendency to act selfishly) but that exogenous shame (not related to a decision at hand) did not. Our study focused on a prosocial behavior tendency towards strangers in a social environment, while de Hooge and her colleagues  focused on behaviors of ‘proselfs’ or ‘prosocials’ in dilemmas. Nevertheless, the present findings are not in line with a later study showing the similar effect of endogenous and exogenous shames on social approach . The social approach studied by de Hooge et al.  is not identical to the everyday helping and donating money in our study. The former focuses on the Withdrawal/Approach choice. The latter refers to the direct help to others and closer to the definition of prosocial behavior. Moreover, the effect of private shame on prosocial behavior was not at the cost of reaction time in the present study, meeting the requirement of speed-accuracy trade-off. Different shame presents different imparts on positive behavior in different prosocial situations, primarily depending on the contribution of a restore motive of shame.
The finding supporting the Hypothesis one could be explained by the functionalism of shame. Fessler  suggested that there are two major social functions of shame expression, namely to seek approval from others and to prevent social exclusion. Shame stems from the exposure of defects. Through the actual evaluation of others or the internalization of others’ evaluations, self-evaluation ultimately triggers shame . A person cares about others' opinions and comments on his own behavior. And shame is more likely to arise from the presence of others . Therefore, shame leads people to pay more attention to their positive image and good reputation in the eyes of others. Shame results in threats to social self-image . In order to maintain a positive self-image, individuals take actions to repair their damaged self, such as limiting the spread of negative information about themselves and preventing the resulting devaluation or negative evaluation of others , which provides a possible explanation for shame promoting prosocial behavior. When violating the rules of the community and expressing shame, one is ready to conform to the group’s standards. In addition, this indicates to others that one is still a potentially valuable cooperation partner and a fully intergraded member of the group. At this time, one is more willing to behave in accordance with the rules of society. The display of shame has been shown to reduce punitive intentions by increasing the perpetrator’s moral sense, and evokes empathy in the observers, which further reduces the punitive intentions .
Compared with public shame, private shame means the defects’ exposure to others is prevented. The help-seeker in prosocial situations knows the individual is going through shameful experiences under the public shame condition in the current study. When a shameful experience is exposed to a partner in interpersonal interaction, it triggers a much stronger restore motive to adopt complementary strategies, such as prosocial behavior, to affirm a positive self-image. Especially in China, social ethics which place particular emphasis on the importance of protecting the public honor of one’s family and community acts as a central framework of social control, encouraging the masking of shameful private behavior with a public veneer of conformity. As long as shame experiences are concealed from the public gaze they can be tolerated. This framework of honor and shame is intrinsically linked to a public–private binary, which restricts the performance of all but normative identities through the constant repetition and restatement of acceptable identities . Perceptions of public shame held by society are uniquely related to having positive attitudes toward seeking help. Individuals are likely to experience both positive and negative messages from those close to them, thus public shame may be more pervasive and represent clearer positive messages about seeking help. Furthermore, over time the public shame that society places on help is bound to change for the positive as well. Prosocial behavior is an optimal way for a person experiencing shame to restore the damaged self, to create a better impression and keep it in public, or to protect his/her damaged self from further damage .
Most importantly, as expected in the Hypothesis two, the present study provides a novel finding that the enhanced effect of public shame on prosocial behavior tendency came out only when help-seeker was a stranger. The roles of help-seekers in prosocial situations, a benefactor or a stranger, have different implications for people experiencing shame. Prosocial behavior is more often taken as repayment and reciprocity if an individual experiencing public shame helps a benefactor compared to helping a stranger. This prosocial behavior highlights an obligation in Chinese culture stressing harmonious interpersonal relationships, abiding by the basic rule “reciprocal altruism” in interpersonal communication [15,16,17], leading to a relative weakening of the restorative effect of shame. On the other hand, prosocial behavior toward a stranger is a better way to eliminate the negative feeling, affirm a positive self, implement the restored motive of shame. When the individual is under the condition of private shame, namely, the shameful experience is not exposed to a stranger, they have no risk to be devalued or despised by the stranger. Under this circumstance, one could maintain a positive self in the eyes of a stranger and more easily behave with kindness to the stranger.
The results also demonstrated a similar pattern of private shame on prosocial behavior tendency towards strangers in everyday helping situation and donating situation. As usual, donating money costs a person more than everyday helping because of cost–benefit analyses . Donating money indeed means a lot for children, as indicated by Wang et al. . However, it does not mean the same to adults who are in the current study. Donating pocket money does not mean a heavy loss for college students and it would not affect their everyday lives. Therefore, in a prosocial situation, whether it be an everyday helping situation or a donating situation, is not an influential factor for adults’ prosocial behavior.
Although this study has yielded some encouraging findings, some limitations still need to be noticed. We set the willingness to help others as an index of prosocial behavior tendency in this study, to measure the influences of emotion on behavior. However, one’s willingness might be different from the actual behavior in the real situation. Therefore, future studies should design a real situation that allows researchers to measure participants’ prosocial behavior. Guilt and shame both have important moral functions, and they are important factors that affect individual's subsequent positive social behavior. Therefore, future studies should design shame and guilt to measure prosocial behavior.
In conclusion, the current study demonstrated that public shame affects prosocial behavior tendency to a stranger. These findings cast light on the relationship between shame and positive behavior, and provide some implications in social interaction.