Fiscal Year
FY 2025
April 2025 – March 2026

Principal Investigator
Yumi Hamamoto
Assistant Professor, Division for the Establishment of Frontier Sciences, Frontier Research Institute for Interdisciplinary Sciences / Research Institute of Electrical Communication

Co-Investigators
Erina Miyatsu
Department of Human Brain Science, Graduate School of Medicine

Research Keywords
Rejection sensitivity ; Perfectionism ; fMRI

1. Research Overview

It is well known that perfectionism is associated with various mental health issues, such as depression, social anxiety, and eating disorders. It has been suggested that this is due to a tendency to anticipate and perceive rejection from others and to overreact to it (rejection sensitivity), which leads to feelings of loneliness in interpersonal relationships. Therefore, clarifying the specific interpersonal contexts in which perfectionists’ rejection sensitivity arises is considered important for understanding related mental health issues. Previous research has suggested that, because perfectionists exhibit characteristic reactions to mistakes, they are likely to perceive rejection when they make a mistake in front of others. However, it has also been pointed out that they may perceive rejection simply due to the presence of others, even in situations where no mistake has been made; thus, it remains unclear in which of these situations rejection sensitivity arises. Therefore, this study used functional magnetic resonance imaging (fMRI) to investigate this question. Specifically, we examined whether individuals with high perfectionism tendencies perceive rejection in situations where others are present and in situations where they make a mistake in front of others. In this study, we focused on several brain regions previously reported in prior research to be associated with social rejection. We examined these brain activities as neural indicators related to the perception of rejection and investigated whether the intensity of this activity correlated with perfectionism scores. The results of the analysis showed a positive correlation between perfectionism scores and activity in some of the brain regions associated with social rejection in both situations, suggesting the possibility that rejection is perceived in both scenarios. Furthermore, since the regions involved differed between the two situations, the findings suggest that sensitivity to rejection in perfectionism is not a single process but may consist of at least two cognitive processes: the process of anticipating and worrying about rejection simply due to the presence of others, and the process of inferring others’ evaluations of oneself based on mistakes made in front of others. This study focused on the neural basis of perfectionism in social contexts and examined “a situation involving making mistakes in front of others” and “a situation where others are present” separately. The results indicated that in individuals with high perfectionism tendencies, neural responses associated with social rejection may be heightened in these interpersonal situations, even when they are not actually being rejected. These findings capture the process by which rejection sensitivity arises in perfectionism at the neural level and contribute to our understanding of mental health issues associated with perfectionism.

2. Significance of the Research and Future Prospects

The findings of this study contribute to elucidating the mechanisms underlying rejection sensitivity, which links perfectionism to mental health issues. In today’s world, where the proliferation of social media and AI has increased the number of situations in which “perfection” is expected, the number of individuals with high perfectionist tendencies is on the rise, and mental health issues related to perfectionism are likely to become an even greater cause for concern. This study is expected to clarify the neural basis of sensitivity to rejection in interpersonal contexts among individuals with high perfectionism tendencies, thereby contributing to the understanding and treatment of related mental health issues. Furthermore, this study holds both academic and clinical significance. From an academic perspective, the novelty of this study lies in its examination of rejection sensitivity—a trait previously studied in the context of perfectionism—to determine in which interpersonal contexts it arises and what neural mechanisms underlie it. From a clinical perspective, the study suggests the importance of focusing not only on the experience of rejection itself but also on the cognitive processes preceding it when providing support for mental health issues related to perfectionism. Finally, by combining psychological questionnaire surveys with brain imaging data (fMRI), this study represents an interdisciplinary effort to understand the psychological trait of “perfectionism” from a neuroscientific perspective. This approach aligns with the philosophy of the So-Go-Chi Project, which aims to comprehensively understand the human mind and brain. Moving forward, we plan to verify whether the cognitive processes identified in this study—such as the anticipation of rejection and hypersensitivity to others’ evaluations—are effective as actual intervention targets, with the expectation that they will be applied to the prevention and treatment of mental health issues related to perfectionism.

3. Conclusion

This study used neuroscientific methods (fMRI) to examine the types of interpersonal situations in which individuals with high perfectionism tendencies may experience rejection from others. The results showed that, regardless of whether the situation involved merely being in the presence of others or making a mistake in front of others, the stronger the perfectionist tendencies, the greater the brain activity associated with social rejection. Furthermore, since different brain regions were involved in each of these two situations, the findings suggest that “hypersensitivity to rejection” is not a single response but consists of at least two cognitive processes: the process of anticipating rejection in advance and the process of attempting to interpret the other person’s intentions when a mistake is made. These findings are expected to contribute to elucidating the mechanisms linking perfectionism to mental health issues.