School bullying refers to behaviors within the school context where an individual or group deliberately or maliciously exerts repeated aggression towards another individual or group, planning to cause psychological or physical harm [1, 2]. For example, incidents of bullying can occur through physical, verbal, and online means, leading to hurtful bullying events. The targets of school bullying are often fixed, embodying characteristics of bullying such as exploiting weaknesses, intentional harm, repeated occurrences, and an imbalance of power. Over time, bullying can significantly impact the mental and bodily well-being of the bully, the victim, and bystanders, distorting their views on education and society, and altering normal behavior patterns. This can result in long-term anxiety, depression, and even life-threatening situations for the victims, while bullies may face retaliation [2–4]. Thus, school bullying is a severe social issue with detrimental effects on both perpetrators and victims. Without effective intervention, bullies may become more involved in societal violence and are at greater risk of substance abuse, legal issues, and criminal behavior (single or repeated) in adulthood [5, 6]. Conversely, victims may experience intense anxiety, depression, loneliness, and helplessness, potentially leading to school aversion, personality disorders, and even suicide in extreme cases [7–10]. Many factors contribute to the occurrence of school bullying, primarily focusing on individual, family, school, and societal aspects, yet personal factors remain a key target in current bullying research.
In recent years, some scholars have discovered [10–12] that participation in sports can reduce the number of school bullying, also affirming that engaging in sports serves as an effective intervention strategy. By increasing physical exercise, it can foster positive peer interactions and emotions, thereby lowering the occurrence of school bullying. Embodied cognition theory posits [13] that the body generates the psyche, suggesting that altering physical posture can change an individual's psychological perception. Given that exercise directly affects the body, promoting more open bodily postures, such postures can swiftly alter an individual's emotional state [14]. Further research has shown [15–17] that long-term engagement in sports can improve an individual's emotional regulation abilities, strategies, and beliefs, reducing deviant behavior among adolescents, enhancing self-control, and enhancing the quality of peer relationships. Precisely, self-control and peer relationships are significant predictors of school bullying occurrences [14]. Thus, scholars have raised the issue: Can participation in sports reduce school bullying? Additionally, studies report that an individual's ability to recognize emotions, process information, and exert self-control are crucial predictors of school bullying [17–20], closely linked to brain executive functions (including emotion management, self-monitoring, working memory, inhibitory control, and attentional flexibility). These executive functions are a function of an individual's social experiences and, in turn, affect social outcomes. Since school bullying is a form of social interaction, bullies and victims exhibit distinct characteristics in executive functioning; bullies often face more difficulties in decision-making processes (tending towards hostility in ambiguous situations), while victims generally have lower behavioral inhibition and cognitive flexibility [21, 22]. Thus, an individual's executive function influences the trajectory of school bullying events. However, more and more studies have started to explore school bullying through the lens of individual sports participation, becoming a new research focus. Engaging in sports can effectively regulate neurotransmitter and hormone levels, improve brain function and neural networks, positively impacting administrative function with a demonstrable causal relationship [23–25]. As executive function improves, bullies' behavioral control abilities and victims' cognitive flexibility and emotional regulation abilities are enhanced. This synergy can effectively reduce the occurrence of school bullying behaviors [14, 26, 27]. Armed with this analysis, this study proposes Hypothesis 1: Participation in sports can significantly negatively predict school bullying.
From the perspective of social control theory, the more an individual values the expectations and opinions of others, the less likely they are to engage in deviant behavior; if individuals do not care about the opinions of those around them and do not wish to meet their expectations, they are more prone to engage in bullying behaviors [28]. In recent years, numerous scholars have explored the relationship between psychological resilience and school bullying, a key topic within positive psychology. Psychological resilience, as a progressive of positive psychological capital, refers to an individual's ability to rapidly respond and adapt to adverse experiences, such as negative life events, dilemmas, setbacks, and threats [29–31]. Individuals with high levels of psychological resilience can quickly recover from current adversities and flexibly adapt to various changes, possessing satisfactory social adaptation and interpersonal skills [32–34]. Additionally, high psychological resilience often manifests as optimistic and positive emotional expression, proactive emotional and self-adjustment in the face of difficulties or adversity, leading to sound decision-making and enhanced problem-solving abilities in interpersonal relationships, thereby helping to reduce the risk of school bullying [35–39]. Studies have confirmed [40–44] that there is a negative correlation between individual psychological resilience and school bullying, and as a protective factor against the risk of school bullying, psychological resilience should receive focused attention in research. It can be leveraged to alleviate the degree of bullying suffered by victims, thereby reducing the occurrence of school bullying. Furthermore, other studies have found [45–48] that sports participation is envisaged a key factor in enhancing psychological resilience among young people. Participation in sports can provide more peer support, improve stress resistance, and enhance interpersonal relationships. The team cooperation and competitive confrontation often accompanying sports participation demand additional willpower and effort from participants, positively affecting students' psychological resilience. Moreover, research by Bordin and Brian also found [12, 49] that sports participation can significantly improve individual levels of psychological resilience, thereby narrowing the occurrence of school bullying. This indicates that sports participation may influence school bullying through psychological resilience, possibly acting as a mediator between sports participation and school bullying. Therefore, this study proposes Hypothesis 2, that psychological resilience mediates the relationship between sports participation and school bullying.
Self-esteem is an individual's emotional evaluation of themselves, either positive or negative, and is a significant predictor of whether health behaviors are adopted [50]. Many scholars believe[32, 38, 39, 51] that students who are frequently bullied tend to score significantly lower on psychological resilience and self-esteem scales than their peers. Students with high levels of self-esteem and psychological resilience are more likely to face difficulties and setbacks with a progressive attitude and coping strategies, experiencing fewer negative emotions, which plays a crucial role in improving interpersonal relationships. Conversely, students with low self-esteem and psychological resilience are prone to a pessimistic outlook on issues, experience more negative emotions, which is detrimental to psychological health development, making them more susceptible to bullying. Studies have also found [30, 52–54] that self-esteem, as an important personal trait, acts as a protective factor against school bullying and enhances psychological resilience. The "protective-protective model" suggests that the predictive effect of one protective factor (psychological resilience) on the outcome variable (school bullying) may vary depending on the level of another protective factor (self-esteem) [55]. Both self-esteem and psychological resilience serve as protective factors against school bullying, where a definite level of self-esteem can enhance psychological resilience and negatively predict the occurrence of school bullying [30, 33, 52–54].
Furthermore, according to problem-behavior theory, an individual's behavior must be examined from a developmental perspective and through the interplay of personality, environment, and behavior. Individuals exhibit behavioral differences due to environmental variations, and similarly, the environment has differing impacts on behavior due to individual differences [56]. The predictive role of psychological resilience in school bullying is not constant under all circumstances but may vary with ecological or personal characteristics. People with high self-esteem often have good peer relationships and tend to adopt positive coping strategies in stressful situations, which enhances psychological resilience and thereby reduces the occurrence of school bullying. Conversely, individuals with low self-esteem are prone to avoidance emotions and lower self-assessment when dealing with stress, potentially leading to decreased social function and lower emotional well-being over time, negatively affecting psychological resilience, and thus making them more susceptible to school bullying [34, 39, 52]. This is expected to result in the speculation that self-esteem may play a moderating role between psychological resilience and school bullying. Enhancing self-esteem can effectively boost psychological resilience, subsequently decreasing the prevalence of school bullying. Therefore, this study proposes Hypothesis 3: Self-esteem moderates the relationship between psychological resilience and school bullying.
In summary, sports participation can influence school bullying through psychological resilience, and self-esteem also affects the relationship between psychological resilience and school bullying. Previous research on school bullying is mainly focused on elementary and secondary education, with few scholars exploring bullying at the university level. Thus, it raises the issue: Does bullying also occur among university students? Additionally, few scholars have investigated the relationship among "sports participation, psychological resilience, self-esteem, and school bullying." This study constructs a moderated mediation model as illustrated in Fig. 1, aiming to explore the mechanisms and boundary conditions—specifically, the mediating role of psychological resilience and the moderating role of self-esteem—between sports participation and school bullying among college students.