Aggression is an individual's hostile response to feelings of threat or frustration (Dodge, 1980). Relational aggression, on the other hand, as a specific form of aggression, usually occurs in the context of social relationships and aims to undermine and threaten another person's social status, reputation, or relationships by means of purposeful interpersonal manipulation, such as rumor-spreading, peer-threatening, intentional ignoring, and group exclusion (Werner & Crick, 1999; Crick, 1996). Relational aggression was first focused on gender differences, and despite extensive investigation by researchers over the last two decades, no definitive answer has yet been reached. For example, initial research suggested that girls were strongly associated with relational aggression due to their own unique high social orientation (Björkqvist, Österman & Kaukianen, 1992; Crick & Grotpeter, 1995; Henington, Hughes, Cavell, & Thompson, 1998); subsequent studies have come to a different conclusion, stating that boys are more inclined to use relational aggression than girls (Kokkinos et al., 2016); however, multiple meta-analyses have shown that relational aggression does not appear to be related to gender (Archer, 2004; Card, Stucky, Sawalani & Little, 2008; Lansford et al., 2012). Based on these findings, some scholars have suggested that the age and development of individuals may be beneficial in explaining this phenomenon (Smith, Rose, & Schwartz-Mette, 2010; Underwood, Beron, & Rosen, 2009). As Crick and Rose (2000) noted in their original study, the incidence of relational aggression may intensify with age compared to physical verbal aggression, which generally decreases with age. Subsequently, a growing body of research has supported this claim and pointed out that relational aggression is a prominent bullying phenomenon in emerging adulthood and is associated with a number of maladaptive factors, such as anxiety, depression, loneliness, stress, academic burnout, alcohol abuse, and impulsive rage (Dahlen et al., 2013; Miller & Lynam, 2003; Ostrov & Houston, 2008; Werner & Crick, 1999). Emerging adulthood is in the midst of the transition from adolescence to adulthood, and its stages of unique developmental changes have been agreed upon by a wide range of researchers, notably in independent living, identity suspension, social relationship turbulence, shifts in moral consciousness, and increased risk-taking behaviors (Arnett, 2000; Spear, 2000). Although there is currently a great deal of investigation by researchers regarding the causes of the formation of emergent adulthood aggression (Gong et al., 2022; Aloia & Pederson, 2021; Elam et al., 2021; Coyne et al., 2020), in the case of relational aggression, the mechanisms of its formation are still in an extensive stage of exploration. Therefore, exploring the mechanisms of relational aggression not only expands the research perspective of relational aggression theory but also has important theoretical value and practical significance for the effective explanation, intervention, and treatment of malignant interpersonal relationships in emerging adulthood.
Social Exclusion and Relational Aggression
Most modern theories and research support the idea that context is an important causative factor in human behavior. As Haney (1983) strongly believed, the determining factor for behavior is the social situation in which we find ourselves. Considering the importance of peer relationships in adolescence, researchers have found that adolescents commonly use relational aggression as an adaptive strategy to change a negative situation, i.e., manipulating social relationships or hurting peers in order to gain popularity and change an otherwise unfavorable social position (Pellegrini et al., 2011; Crick & Grotpeter, 1995; Long & Li, 2020). However, it is interesting to note that some research suggests that emerging adulthood has the same popularity claims as late adolescence and that unpopular people are more likely to engage in relational aggression (LaFontana & Cillessen, 2010). Based on these phenomena, we suggest that social exclusion, as a negative context of unpopularity and non-acceptance, may be related to relational aggression in some way. In the field of social psychology, scholars have tended to view social exclusion as a concept opposed to social acceptance, and the everyday events associated with it mainly include rejection (discrimination, stigmatization, dehumanization, or microaggressions) (Andrighetto et al., 2016; Richman et al., 2016; Sue et al., 2007) and neglect (being forgotten, not answering, or refusal of eye contact) (Dotan-Eliaz et al., 2009; King & Geise, 2011; Nezlek, 2012; Wesselmann, 2017). In light of the adverse effects of social exclusion, researchers have done investigations and found that adults who are chronically socially excluded show more emotional dysregulation and aggressive tendencies compared to adults who are not socially excluded (Bochon, Bird & Watson, 2023; Hajek, Kretzler & König, 2021; Rajchert et al., 2023; Lasko et al., 2022). According to Williams' demand-threat temporal model, the negative emotions aroused by an individual's encounter with social exclusion pose a threat to his or her basic psychological needs, which in turn leads the individual to engage in antisocial behavioral strategies towards the source of exclusion (Williams, 2009). At the same time, the general aggression model also states that individuals, under conditions of their own resourcefulness, will adopt risky behaviors and strategies as an immediate manifestation of self-defense if they are unfairly treated or unjustifiably excluded (Allen & Bushman, 2018). However, while current theoretical relationships and empirical research on social exclusion and aggression have made good research progress across different research samples (Brennan et al., 2018; Stenseng et al., 2014), the unique link between social exclusion and relational aggression in emerging adulthood has not yet been explicitly validated. Therefore, the present study hypothesizes that social exclusion may be an important stimulus leading to relational aggression in emerging adulthood.
The Mediating Role of Relative Deprivation
Social exclusion, as an external situational factor leading to poor behavior, does not necessarily affect an individual's external behavior directly; it may also play a role through a psychological state, i.e., a sense of relative deprivation. This concept, first proposed by the American scholar S. A. Stouffer and later developed by R. K. Merton into the theory of group behavior, refers to the subjective feeling that arises when people compare their situation with a certain criterion or a certain reference and find themselves at a disadvantage or in an unsatisfactory social position (Stouffer et al., 1949; Merton, 1957; Bernstein & Crosby, 1980; Smith et al.). According to the theory of relative deprivation, when people make social comparisons with others to assess their social situation, the weaker party perceives a more intense experience of deprivation, which subsequently triggers maladaptive emotions or behavioral problems (Mummendey et al., 1999). Therefore, we believe that social exclusion, as a situational state that is oppositely structured between the dominant party (the excluder) and the disadvantaged party (the excluded), is likely to be an important trigger of relative deprivation for the disadvantaged party. On the other hand, a large number of studies have consistently demonstrated a strong association between relative deprivation as a macro-psychosocial factor and aggressive behavior. For example, adolescents with higher levels of deprivation are more likely to engage in aggressive behavior (Li et al., 2023; Liang, 2020); similarly, adults who perceive themselves to be relatively deprived are associated with more cyber-attacks and real-life attacks (Zhou, 2023; Zhang & Zhang, 2023; Peng et al., 2021). Considering that the exact mechanism by which relative deprivation plays a role in social exclusion and relational aggression has not been validated, Therefore, the present study hypothesized that relative deprivation may be an important mediator of social exclusion leading to relational aggression in emerging adulthood.
The Moderating Role of Hostile Attribution Bias
In his study, Dodge (2011) mentioned that "if an individual believes that another person's offense against him or her is unintentional, the likelihood that the individual will react aggressively is very high (approximately 0.76); similarly, if the individual believes that another person's offense is not intentional, the likelihood of reacting aggressively is very low (approximately 0.25).". Hostile attribution bias, defined as the tendency to contextually reason about hostile intentions toward others when social contextual cues are unclear, is a key factor in the etiology of problem behaviors (Milich & Dodge, 1984). Based on the social information processing theory SIP, the interpretations individuals make of social events influence their behavioral responses, with internal and external attributions playing a determining factor (Dodge & Crick, 1996). Specifically, when an exclusionary event occurs, internal attributions cause individuals to search for the cause in themselves, which leads to pro-social behaviors to seek social connections, whereas external attributions attribute the event to others and trigger antisocial or transgressive behaviors (Guo, 2014). Thus, hostile attribution bias, as a manifestation of external attribution, is likely to play an important catalytic role between social exclusion and relational aggression. Research suggests that hostile attributional bias is an important cognitive mechanism for triggering relational aggression. For example, in a study of children with oppositional disorders, it was shown that children with a high hostile attributional bias pay more attention to negative social cues and make false prejudgements about possible negative threats, which in turn trigger relational aggression (de la Osa et al., 2018). At the same time, emerging adult relational aggression is uniquely associated with hostile attributional bias in conflict provocation, which may exacerbate the frequency of oppositional behaviors and relational aggression with others when levels of hostile attributional bias are high (Bailey & Ostrov, 2008). Although previous research has provided evidence for a link between hostile attributional bias and relational aggression, this link has not been widely validated in emerging adulthood. Therefore, the present study hypothesized that high hostile attributional bias, as a risk factor, may exacerbate the impact of social exclusion on relational aggression in emerging adulthood.
The Current Study
Based on existing theories and research, this study aims to explore the effects of social exclusion on relational aggression in emerging adulthood and the potential mechanisms of relative deprivation and hostile attributional bias, to provide new and useful information about the mechanism of generating relational aggression in emerging adulthood, and to construct a mediated moderation model based on this (Fig. 1). We formulate the hypotheses:
H1: Social exclusion positively predicts emerging adult relational aggression.
H2: Relative deprivation mediates the relationship between social exclusion and emerging adult relational aggression.
H3: Hostile attributions moderated the effect of social exclusion on emerging adult relational aggression.