Body Dissatisfaction and Social Anxiety among Adolescents: A Moderated Mediation Model of Feeling of Inferiority, Family Cohesion and Friendship Quality

Previous research has documented that body dissatisfaction is positively related to social anxiety. However, little is known about the mediating and moderating mechanisms underlying this relation. Based on person-environment interaction theory, this study aimed to examine the chain mediation effect of feeling of inferiority and family cohesion in the relationship between body dissatisfaction and social anxiety among adolescents and whether this mediating process was moderated by friendship quality. A total of 972 students (M = 15.77, SD = 0.856) were enrolled in this study. All participants completed questionnaires regarding adolescent body dissatisfaction, feeling of inferiority, family cohesion, friendship quality and social anxiety. Our study found that body dissatisfaction was positively associated with social anxiety. Feeling of inferiority and family cohesion were found to play a chain-mediated role in the relation between body dissatisfaction and social anxiety. In addition, friendship quality plays a moderating role in the relationship between body dissatisfaction and social anxiety. According to the person-environment interaction theory, this study not only confirms the effect of body dissatisfaction on social anxiety in a collectivist culture, but also reveals the mechanism of the role of individual characteristics (feeling of inferiority) and external environmental factors (family cohesion) in the relationship between body dissatisfaction and social anxiety, and the moderating effect of friendship quality on the whole mechanism. These findings show lights on how body dissatisfaction is associated with social anxiety in adolescents.


Introduction
Social anxiety disorder is one of the top five functionally impairing psychological disorders (Investigators et al., 2004), which is characterized by an early age of onset (Asher et al., 2017;Chen et al., 2021) and is the most prevalent in adolescence (Ollendick & Hirshfeld-Becker, 2002) with 15% prevalence rates (Heimberg et al., 2000). The data from the U.S. National Comorbidity Survey (NCS) shows that the lifetime prevalence of social anxiety disorders is 13.3% in the United States (Kessler et al., 1994). Social anxiety refers to anxious anticipation, depression, and strong fear of negative evaluation in social situations (Beidel & Turner, 2007), which can seriously damage the mental health of adolescents and may lead to insomnia (Buckner et al., 2008), mood disorders (Buckner et al., 2006), poor relationships (Heerey & Kring, 2007), academic difficulties and school dropout (Ruscio et al., 2008).
During adolescence, body and appearance undergo dramatic changes , which will affect the formation of body image, and body dissatisfaction reaches its peak (Bucchianeri et al., 2013). According to the cognitive model of social anxiety disorder, distorted and negative self-image is a key factor in the maintenance of social anxiety (Hodson et al., 2008). Simultaneously, teenagers will face the pressure of social interaction with surrounding classmates, teachers, and parents. This makes them more prone to social anxiety (Rapee & Spence, 2004).
As the research on the relationship between body dissatisfaction and social anxiety in adolescents continues to intensify, related scholars have begun to explore its deeper mechanisms. Previous research have focused more on the mediating (moderating) role of individual psychological characteristics or environmental factors in the relationship between body dissatisfaction and social anxiety, such as fear of evaluation (Pawijit et al., 2019),emotion regulation strategies (Schaefer et al., 2015), beliefs (Dobinson et al., 2019) and ethnicity (BeLue et al., 2009). The person-environment interaction theory emphasizes that there is a complex interaction between individual characteristics and the environment, and the degree of environmental influence on individual development may be enhanced or diminished by certain personal factors (Burmeister et al., 2008).The adaptation theory proposed by Ladd (1988) considers social interaction as a result of the interaction between individual characteristics and interpersonal contexts. This study, therefore, aimed to examine the association of body dissatisfaction and social anxiety among adolescents, as well as the role of individual (feeling of inferiority) and environmental factors (family cohesion, friendship quality) in this relationship.
Previous research has focused more on the mediating (moderating) role of individual psychological characteristics or environmental factors between physical dissatisfaction and social anxiety, such as fear of evaluation.Meanwhile, the information processing model of social anxiety states that socially anxious individuals place undue importance on the pressures of the social environment, focusing on what others think of them and develop anxiety (Clark & McManus, 2002). According to self-construal theory, individuals in collectivist cultures conceptualize themselves as dependent self and see themselves as an extension of the social group to which they belong (Markus & Kitayama, 1991), and are highly dependent on interpersonal relationships, so they place more importance on the feelings of others and care about their evaluations (Hui & Triandis, 1986). Based on this, one of the purposes of this study was to verify that body dissatisfaction is positively related to social anxiety in a collectivist culture.

Body Dissatisfaction and Social Anxiety in Adolescents
Body image, as a central to self-concept formation (Cash, 2004), can be divided into positive body image and negative body image. When individuals have negative evaluations of their bodies and high levels of dissatisfaction, he will experience negative body image, conceptualized as body dissatisfaction (Gattario & Frisen, 2019). It can damage one's mental health and social activities, especially for adolescents.
People with body dissatisfaction report more negative evaluations of their appearance (Barnier & Collison, 2019) and worry that others have negative evaluations of them, which leads them to experience more anxiety in social interactions (Pawijit et al., 2019). Studies also showed that patients with body dysmorphic disorder have higher levels of social avoidance and distress than healthy group (Pinto & Phillips, 2005). An experimental study found that compared with simply discussing the negative images, participants' anxiety about social situations was significantly improved after cognitive restructuring of the negative images through contextual updating of memory (Wild et al., 2008). Therefore, this study proposes hypothesis 1: Body dissatisfaction is significantly positively correlated with social anxiety.

The Mediating Role of Feeling of Inferiority and Family Cohesion
Inferiority is a psychological structure emphasized in Erikson's psychosocial theory and Adler's personal psychology (Çelik & Ergün, 2016). It is a subjective feeling produced by comparing oneself with others (Strano & Dixon, 1990). Body dissatisfaction as the basis of individual self-concept (Shin & Nam, 2015) is closely related to mental health (Gattario & Frisen, 2019) and may lead to depression and low self-esteem . For example, people with body dissatisfaction would control their body shape by dieting and other means to avoid the feeling of inferiority (Bellew et al., 2006). It is argued that individuals who experience excessive indulgence or neglect early in development are more likely to feel inferior and develop problems with social relationships (Adler, 1996). Besides, social hierarchy theory suggests that emotions are largely influenced by a person's perception of social status/hierarchy (Gilbert, 2016), when a person perceives that he or she possesses some traits that others do not recognize or lacks valuable abilities (e.g., lack of physical attractiveness, motor skills), he or she feels low in terms of value, self-esteem, and is more likely to develop submissive behaviors such as depression, shame, and social anxiety (Gilbert & McGuire, 1998). Accordingly, this study proposes hypothesis 2: Feeling of inferiority plays a mediating role in the relationship between body dissatisfaction and social anxiety.
Family cohesion refers to the perceived level of emotional bonding in the family, and it is expressed by feeling of belongings and acceptance (Liu et al., 2014). Most previous studies have focused on the influence of family cohesion on children's body dissatisfaction (Holsen et al., 2012;McCabe & Ricciardelli, 2003), but few on the opposite influence. During adolescence, children pay more attention to appearance due to the increase of body dissatisfaction (Gattario & Frisen, 2019), which makes them always comes into conflict with parents (Fang & Dong, 1998). Study also found that individuals who were dissatisfied with their appearance were more isolated and less likely to communicate with others (Kılıç & Karakuş, 2016), which may further affect family cohesion. The family functioning theory illustrates that the positive family environment plays an important role in the development of adolescent psychological and social functioning (Miller et al., 2000). In dysfunctional families, less communication and interaction among family members will cause a decrease in the sense of belonging and responsibility, which influence children's social adaptation (Kuhlthau et al., 2010). As a comprehensive indicator reflecting family members' affinity and positive family atmosphere, family cohesion is thought to protect against anxiety and depression (Cumsille & Epstein, 1994;Qu et al., 2021). Based on this, this study proposes hypothesis 3: Family cohesion plays a mediating role in body image distress and social anxiety.
Although both feeling of inferiority and family cohesion may be mediating variables between body dissatisfaction and social anxiety, there may be a connection between them. Family systems theory suggests that the family is composed of a set of interacting subsystems, all of which are complementary to each other (Minuchin, 1985). Accordingly, Bolger et al. (1989) proposed the "spillover effect" to understand the interactions among family subsystems. The spillover effect refers to the effect of one person's emotional experience on parents' (White, 1999). Feeling of inferiority is positively correlated with negative emotions, such as anxiety and depression (Adler, 1970;Chen et al., 2020), and it may make parents more prone to negative emotions. In turn, it is not conducive to family cohesion. Based on this, hypothesis 4 is proposed: Feeling of inferiority and family cohesion may play a chain mediating role in the effect of body dissatisfaction on social anxiety.

The Moderating Effect of Friendship Quality
During adolescence, children gradually reduce their dependence on their parents and interact with friends more frequently (Brown & Larson, 2009), and the quality of friendships has an important impact on adolescents' psychology and behavior (Demir et al., 2007;Goswami, 2012). Friendship quality refers to the degree of companionship, intimacy, and security between friends (Gauze et al., 1996). High friendship quality can not only provide adolescents with external peer support, but also enhance their inner sense of self-worth (Troop-Gordon et al., 2015). The risk-buffering model suggests that positive factors in the environment can mitigate the adverse effects of risk factors (Hollister-Wagner et al., 2001), and that high friendship quality as a positive factor in the life environment can protect individuals when they experience negative events. In addition, the study also found that friendship quality provided important social support for adolescents (Giletta et al., 2017). According to the buffer theory of social support, social support perceived by individuals can enhance their ability to cope with stress and counteract the adverse effects of risk factors (Cohen & Wills, 1985). People with body dissatisfaction may develop feeling of inferiority, but if they have high-quality friendships, they can get additional social support, which will alleviate the feeling of inferiority caused by body dissatisfaction, and vice versa. Based on this, this study proposes hypothesis 5: For adolescents, the influence of body dissatisfaction on feeling of inferiority will be moderated by friendships quality.
In summary, this study constructed a moderated chain mediation model (see Fig. 1) based on the theory of person-environment interaction. The main purposes include: (1) examining the relationship between body dissatisfactions and social anxiety in a collectivist culture; (2) exploring the chain mediating role of feeling of inferiority and family cohesion on body dissatisfaction and social anxiety; (3) exploring the moderating effect of friendship quality on body dissatisfaction and social anxiety.

Materials and Method
This study was approved by the ethics committee of the institution to which the authors belong. The study was conducted with the consent of the students themselves and their parents, and the class teacher asked the students to complete the relevant questionnaire content during 45 min of class time. All students were informed in advance that the results would not affect their academic performance. The study was conducted under strict confidentiality and anonymity and subjects had the right to withdraw at any time.

Participants
The whole group sampling method was used in this study. 19 classes in a general high school in Huaibei City, Anhui Province were asked to complete the surveys, 972 questionnaires were distributed, and after eliminating invalid and missing responses, 924 valid questionnaires were finally obtained, with an effective rate of 95.06%. The final students ranging from 14 to 19 years old (M = 15.77, SD = 0.855). Among them, 561 (57.7%) were male students and 411 (42.3%) were female students; 549 (59.42%) were senior students, 276 (29.87%) were sophomores, and 99 (10.71%) were senior three students. There were 684 (74.03%) resident students and 240 (25.97%) non-resident students. There were 265 (28.68%) only children and 659 (71.32%) non-only children. 845 (91.45%) were two-parent families, 66 (7.14%) were single-parent families, and 13 (1.41%) were another family structure. Parents' economic income: 1.62% of the families had a monthly income of less than 1000 yuan, 5.84% had a monthly income of 1000 to 3000 yuan, 24.57% had a monthly income of 3000 to 5000 yuan, 35.93% had a monthly income of 5000 to 8000 yuan, and 32.03% had a monthly income of more than 8000 yuan. 32.03% of the families had a monthly income of 8000 yuan or more. Parents' education level: 54.11% of fathers and 62.12% of mothers have junior high school education or less, 27.49% of fathers and 23.81% of mothers have high school education, 12.45% of fathers and 9.85% of mothers have college education, 5.95% of fathers and 4.22% of mothers have bachelor degree or above.

Adolescent Body Dissatisfaction
The Adolescent Body Dissatisfaction scale is compiled and tested for reliability by Gao et al. (2005), and consists of 25 items that assess appearance, body, organs and gender dissatisfaction on a 3-point Likert scale with values ranging from 1 as conform to 5 as not conform. An example item is "I am always dissatisfied with my body shape." The lower the score, the higher the level of body dissatisfaction. Reliability analysis revealed a high degree of internal consistency as indicated by Cronbach's α = 0.844.

Feeling of Inferiority
The "Feeling of Inferiority Scale for College, Middle and Primary School Students" compiled and tested for reliability by Li and Kong (2010) has 22 items, including four dimensions: life inferiority, social inferiority, academic inferiority, and character inferiority. One sample item is, "I feel inferior to him/her because I don't have the superior living conditions as him/her". Each item is answered ranging from ''never'' to ''always'' and each response is assigned a score from 1 to 5. The higher score denotes higher feeling of inferiority. The scale achieved good inter-item reliability with the current sample (Cronbach's α = 0.931).

Family Cohesion
The Cohesion subscale of the Family Adaptability and Cohesion Scale (FACES) was used to measure family cohesion (Olson, 1983), which was revised by Fuligni and Zhang (2004) and tested for reliability. The subscale contains ten questions that should be answered twice for father and mother separately. An example item is "My parents and I support each other in times of difficulty. The test questions are scored on a 5-point Likert scale ranging from 1 = never to 5 = always. Higher averaged scores represent higher levels of family cohesiveness. In our sample, the Cronbach's alpha for this scale was 0.842.

Friendship Quality
The friendship quality was measured by an 18-item scale, which was adapted from the Friendship Quality Questionnaire (FQQ) developed by Parker and Asher (1993), and it was revised by Zhou et al. (2006a, b) and tested for reliability. Participants were asked about the feeling with the best friend, such as "We always sit together whenever we get the chance", then responded to all questions on a 5-point scale that was score from 1 = not conform at all through 5 = totally conform. A higher score indicates that the participants perceive a higher quality of friendship (Zhou et al., 2006a). In our sample, the Cronbach's alpha for this scale was 0.832.

Social Anxiety
Social anxiety of the adolescents was assessed by the 19-item Chinese version Social Responsibility Scale, which was developed by Mattick and Clarke (1998) then revised by Ye et al. (2007) and tested for reliability. The sample items include, "It's difficult for me to make eye contact with others". The scale was rated on a 5-point Likert scale from 1 (strongly disagree) to 5 (strongly agree) and higher score indicated higher social anxiety. In our sample, the Cronbach's alpha for this scale was 0.891.

Data Analyses
Statistical analyses were performed using SPSS 26.0 and the Process 3.5 macro program, including descriptive statistical analysis, correlation analysis, regression analysis, and test of moderating and mediation effect.

Common Method Bias
Restricted by objective conditions, the data of all variables in this study were collected by the self-report of the participants, and the relationship between variables may be affected by common method bias. According to the suggestions of Zhou and Long (2004), corresponding controls were carried out in terms of procedures, such as protecting the anonymity of the participants and reducing the guess about the purpose of the measurement. To further improve the rigor of the study, Harman's factorial factor analysis was used to test the common method bias before analyzing the data. The results showed that there were 27 factors with eigenvalues greater than 1 when unrotated, explaining 65.20% of the variance, and the first main factor explains 12.64% of the variance, far less than the critical value of 40%. Therefore, there is no serious common method bias in this study. Table 1 shows the descriptive statistics and correlation analysis results for each variable. Body dissatisfaction and feeling of inferiority have a positive correlation with social anxiety and negative correlation with family cohesion. Friendship quality was significantly positively correlated with family cohesion, while friendship quality and family cohesion were significantly negatively correlated with social anxiety. There was a significant positive correlation between feeling of inferiority and body dissatisfaction, and a significant negative correlation with friendship quality. There was a small significant correlation between body dissatisfaction and friendship quality, indicating that the independent variable and the moderator variable were relatively independent, which was suitable for the subsequent moderation effect test (Wen et al., 2005). Sex is a dummy variable, male = 0, female = 1, and the mean represents the proportion of females * p < 0.05, ** p < 0.01, ***p < 0.001, the same below

The Relationship between Body Dissatisfaction and Social Anxiety: A Moderated Mediation Model Test
The results of correlation analysis showed that the relationship between body dissatisfaction, family cohesion, friendship quality, feeling of inferiority, and social anxiety met the conditions for a moderated mediation model test. In the process of result analysis, this study used gender, age, grade, whether the student was an only child, whether the student lived in school, family structure, father's education level, mother's education level, and monthly household economic income as control variables, and centralized all predictors (Hayes, 2013), and the variance inflation factors of all predictors were lower than 2. There was no multicollinearity problem. After controlling for control variables, model 6 in the IBM SPSS macro program PROCESS compiled by Hayes was used to explore the chain mediating effect of feeling of inferiority and family cohesion in body dissatisfaction and social anxiety (see Table 2). The results showed that body dissatisfaction had a significant predictive effect on social anxiety (β = 0.30, t = 9.06, p < 0.001). After introducing the feeling of inferiority and Table 2 The mediating effect test of social anxiety Grade, whether the student was an only child, whether the student lived in school, family structure, father's education level, mother's education level, and monthly household economic income were used as covariates BD body dissatisfaction, SA social anxiety, FI feeling of inferiority, FC family cohesion family cohesion, the predictive effect of body dissatisfaction on social anxiety was still significant (β = 0.15, t = 4.73, p < 0.001), in which body dissatisfaction has a significant positive predictive effect on feeling of inferiority (β = 0.35, t = 10.98, p < 0.001), and feeling of inferiority had a significant positive predictive effect on social anxiety (β = 0.33, t = 10.7, p < 0.001); body dissatisfaction had a significant negative predictive effect on family cohesion (β = -0.11, t = -3.01, p < 0.01), and family cohesion had a significant and negative predictive effect on social anxiety (β = -0.16, t = -5.29, p < 0.001).
The results of the mediation test (see Table 3) showed that the upper and lower bounds of the Bootstrap 95% confidence interval of the direct and the chain mediating effect did not contain 0, indicating that body dissatisfaction could not only directly predict adolescents' social anxiety but also significantly predict it through the mediating effect of feeling of inferiority and family cohesion, which verifies the existence of the mediating effect of social anxiety, and the mediating effect accounted for 49% of the total effect. Further, the moderating mediating role of friendship quality between body dissatisfaction and social anxiety was analyzed (Table 4). After controlling for variables such as gender and age, Model 83 in PROCESS, an IBM SPSS macro program developed by Hayes, was used to test. The results show ( Table 5) that the judgment index is -0.00 with a confidence interval of [-0.00, -0.00] and a confidence interval that does not contain 0, again indicating a significant mediating effect with moderation (Hayes, 2017). Overall, the chain mediating role of feeling of inferiority and family cohesion between body dissatisfaction and social anxiety was significantly diminished as the friendship quality improved.
To further analyze the trend of moderating effect of friendship quality, which was divided into two groups of high and low by mean score plus or minus one standard deviation to test the difference. First, the moderating effect of friendship quality between body dissatisfaction and feeling of inferiority. The results showed (Fig. 2) that body dissatisfaction significantly predicted feeling of inferiority when friendship quality was high (βsimple = 0.44, t = 6.85, p < 0.05), while body dissatisfaction also significantly predicted feeling of inferiority when friendship quality was low (βsimple = 0.67, t = 10.25, p < 0.05). This suggests that friendship quality has a moderating effect on the relationship between body dissatisfaction and feeling of inferiority.

Discussion
According to person-environment interaction theory, this study proposed a moderated mediation model and revealed that body dissatisfaction was positively associated with social anxiety. Feeling of inferiority and family cohesion were found to play a chain-mediated role in the relationship between body dissatisfaction and social anxiety. In addition, friendship quality plays a moderating role in the relationship between body dissatisfaction and social anxiety. These findings show light on how body dissatisfaction is associated with social anxiety in adolescents.

The Relationship between Body Dissatisfaction and Social Anxiety
The present study suggested that higher body dissatisfaction is associated with higher social anxiety among adolescents, confirming past finding with adult samples (Chen et al., 2022;Vassilopoulos, 2005), as well as with adolescents (Hodson et al., 2008). The findings supported the initial hypothesis and further supported the cognitive model of social phobia (Clark & Wells, 1995), that the self-image in the mind of social phobia is negative and partially distorted. Hulme et al. (2012) proposed that the self-memory system is responsible for the retrieval of self-related information in a specific context, and the self-image represents the working self in the self-memory system. A positive self-image can produce a positive working self (Hulme et al., 2012). Experiments have shown that participants who produce positive self-images always use emotion regulation strategies and experience less anxiety and discomfort Fig. 2 The moderating effect of friendship quality on the relationship between body dissatisfaction and feeling of inferiority. When the friendship quality was high, body dissatisfaction significantly predicted feeling of inferiority (βsimple = 0.44, t = 6.85, p < 0.05), and when it was low, body dissatisfaction also significantly predicted feeling of inferiority (βsimple = 0.67, t = 10.25, p < 0.05) (Lee et al., 2019). When faced with body-related stimuli, people with body dissatisfaction were significantly less likely to spontaneously use rational emotion regulation strategies, such as cognitive reappraisal (Schaefer et al., 2015). In social situations, unreasonable emotion regulation strategies can maintain or increase social anxiety (Spokas et al., 2009). Thus, there was a significant negative correlation between body dissatisfaction and social anxiety.

The Chain Mediating Effect of Feeling of Inferiority and Family Cohesion
Consistent with Hypothesis 2, this study shows that feeling of inferiority plays a partial mediating role in the relationship between body dissatisfaction and social anxiety. Due to the dramatic changes in physiology, cognition, and emotions that occur during adolescence, adolescents pay more attention to their bodies. Existing studies have found that body dissatisfaction in both boys and girls increases dramatically during adolescence and plateaus in early adulthood (Bucchianeri et al., 2013;Gattario & Frisen, 2019). Adolescence is also a critical period for the formation of selfesteem (Harter & Leahy, 2001). When adolescents feel dissatisfied with their body image, they may experience negative emotions (e.g., disappointment, shame) (Conradt et al., 2007) and poor self-esteem (Davison & McCabe, 2006;French et al., 1996). While shame is often caused by not meeting a certain standard (Pila et al., 2015), low self-esteem is a sense of low value or low ability (Duchesne et al., 2017). And feelings of inferiority arise when individuals feels that he is inferior to someone in some way, or he does not meet the standard (Adler, 1996;Yao et al., 1996). Thus, body dissatisfaction was positively correlated with feeling of inferiority, and this finding was consistent with those from previous studies (BeLue et al., 2009;Gupta & Gupta, 2013;Koo, 1995). People with high level of feeling of inferiority always perceive the environment as threatening (Adler, 1996), which may lead to low levels of social interest (Akdoğan, 2017;Brough, 1994) and social avoidance (Akdoğan & Çimşir, 2019). Therefore, people with feeling of inferiority are more likely to show social anxiety in social situations. Previous research found that compared with nonsocially anxious people, people with social anxiety have more negative evaluation of themself and their social performance (Dodge et al., 1988).
In addition, the study show that adolescents' body dissatisfaction indirectly affects their social anxiety through family cohesion. The higher level of body dissatisfaction in adolescents, the lower the family cohesion, and the more obvious social anxiety. Hypothesis 3 is supported. Considerable research has demonstrated that individuals with high family cohesion show less body dissatisfaction (Anschutz et al., 2009;Golan & Crow, 2004). However, to our knowledge, little existing research has tested the influence of body dissatisfaction on family cohesion. Our finding elucidates the function of family cohesion in the relationship between body dissatisfaction and social anxiety. Most adolescents experience a sharp increase in body dissatisfaction during early adolescence (Grogan, 2021), while studies on Chinese families have found that appearance is one of the main sources of parent-child conflict, and it is difficult for both parties to reach a consensus (Fang & Dong, 1998). In the face of conflicts, parents and adolescents more often adopt passive, negative, confrontational or avoidant ways (Riesch et al., 2003), which cannot achieve effective communication (Montemayor, 1986) and are not conducive to problem-solving, and then it will damage the parent-child relationship. As a dimension of parent-child relationship, family cohesion will also be affected (Olson, 1983).
Studies have confirmed that a positive and harmonious parent-child relationship is conducive to the establishment of a secure attachment relationship, improves emotional security, and reduces the occurrence of behavioral problems (Beavers & Hampson, 2000), while negative parent-child attachment will damage children's interpersonal relationships and increase the incidence of behavioral problems, social anxiety and risk of depression (Bögels & Brechman-Toussaint, 2006). Therefore, family cohesion has a negative predictive effect on adolescent social anxiety (Johnson et al., 2001;Wentzel & Feldman, 1996).
This study also found that feeling of inferiority and family cohesion play a chainmediated role in the relationship between body dissatisfaction and social anxiety. The higher level of body dissatisfaction in adolescents, the stronger the feeling of inferiority, and the lower the family cohesion. Hypothesis 4 was verified. According to Erikson's psychological development theory, the main developmental task of adolescence is to explore self-identity (Erikson, 1993). Children's attitude towards their parents has changed from compliance and dependence to separation and attachment (Grotevant & Cooper, 2009), and they want to gain more independence and autonomy. Getting rid of parental control (Steinberg & Silverberg, 1986) leads to an increase in parent-child conflict (Galambos & Almeida, 1992). Studies have found that people with high feeling of inferiority are more likely to experience negative emotions such as depression, loneliness, hostility (Akdoğan & Ceyhan, 2014), and behaviors like insomnia and suicide (Lee, 2008). On the one hand, children's emotional and behavioral problems will bring great psychological pressure to their parents (Blanchard et al., 2006). On the other hand, children with a strong sense of inferiority think that they are not worthy of being loved (Adler, 1996) and tend to hide themselves and not communicate in the face of conflicts (Akdoğan, 2017). These are detrimental to the development of family cohesion, and further affect the level of social anxiety.

The Moderating Effect of Friendship Quality
This study found that friendship quality not only had a negative predictive effect on feeling of inferiority, but also moderated the mediating role of feeling of inferiority in the relationship between body dissatisfaction and social anxiety. At low levels of friendship quality, body dissatisfaction can significantly predict feeling of inferiority, while high levels of friendship quality can effectively buffer the negative effects of body dissatisfaction, hypothesis 5 is validated. First, according to social comparison theory, when individuals compare themselves with others, they may have feelings of inferiority, which will reduce their sense of self-worth and produce painful emotional experiences (Tiedens et al., 2004). But high-quality friendships can provide individuals with safety, support, and promote a sense of self-worth (Bukowski et al., 1994), all of which can help alleviate an individual's sense of inferiority.
Body Dissatisfaction and Social Anxiety among Adolescents:… Second, high quality friendship means that individuals can get more social support from friends (Rubin et al., 2004), which can increase their psychological capital to cope with stressful events (Demır & Weitekamp, 2007), so friendship quality is often act as a protective factor on for negative psychology, thereby affecting the effect of risk factors on the individual's psychology. High friendship quality can not only provide adolescence with external social support, obtain spiritual comfort and a sense of belonging (Lacourse et al., 2003), but also improve individual pleasure, happiness and inner sense of self-worth (Demır & Weitekamp, 2007;Troop-Gordon et al., 2015), thereby alleviating the feeling of inferiority caused by body dissatisfaction. Individuals with low friendship quality are prone to conflict with others (Rubin et al., 2006), and lack the ability and skills to regulate negative emotions due to the lack of effective communication and experience sharing among peers (Buhs et al., 2006), which is not conducive to the relief of feeling of inferiority. In conclusion, body dissatisfaction increases the likelihood of social anxiety through feeling of inferiority, but high levels of friendship quality can reduce feeling of inferiority through improved self-worth.

Strengths, Limitations, and Future Directions
As mental health issues of concern to adolescents, body dissatisfaction and social anxiety have been of interest to researchers in terms of their effects on psychological development. This study not only confirms the effect of body dissatisfaction on social anxiety in a collectivist culture, but also reveals the mechanism of the role of internal psychological factors (feeling of inferiority) and external environmental factors (family cohesion) in the relationship between body dissatisfaction and social anxiety, and the moderating effect of friendship quality on the whole mechanism, based on the theory of individual-environment interaction. When students are in adolescence, the relative instability of emotional states, relative cognitive immaturity, and complex interpersonal relationships may all increase the risk of social anxiety. This study provides theoretical guidance and empirical evidence for how to alleviate adolescent social anxiety. First, it is necessary to pay full attention to the role of body dissatisfaction in adolescents' social anxiety. Educators need to guide adolescents to have a better attitude toward appearance and relieve adolescents' feeling of inferiority and social anxiety caused by body dissatisfaction. Secondly, parents need to pay more attention to the emotional development with their adolescent children rather than just academic achievement, providing them with a good family environment, psychological support and skills to make friends, etc., so as to improve the children's ability to turn negative emotions into positive emotions, thereby reducing the possibility of children's social anxiety. It is of great significance to promote their mental health development.
However, some limitations of our study should be noted. First, this study used cross-section data to assess the link among variables during adolescence, which cannot reveal the causal relationship between variables, and can only infer the relationship between variables during adolescence, the environment and interpersonal communication styles of individuals after puberty will change. Future research needs to further identify and explore the relationship between the above variables and their dynamic changes. Second, variables in this study all were exclusively assessed by self-report measure, the measure of family cohesion is the child's perception rather than actual family cohesion, although the former may have a greater impact on adolescent development and adaptation than the latter, but to understand the role of family cohesion more fully, future research would benefit from using multi-informant reports of family cohesion (such as using both parent reports and adolescent selfreports). Finally, according to the Bioecological Model (Bronfenbrenner & Morris, 2007), the environmental systems that influence the psychological development of adolescents can be divided from small to large: micro (the environment in which the individual is directly involved), meso (the connection between various microsystems related to the individual), extrinsic (the environment in which the individual is not directly involved, but which has an impact on him/her) and macro (the general social environment and culture in which the individual is located). Family cohesion and friendship quality, as factors directly associated with adolescents, can be considered as important organizational components of the microsystem, while the interaction between the two environments is also a component of the mesosystem. Considering the complexity of the model, this paper does not provide a more in-depth discussion, and future studies can go deeper.

Conclusion
Adolescent body dissatisfaction can positively predict social anxiety. Feeling of inferiority and family cohesion have a chain mediating effect between body dissatisfaction and social anxiety. Meanwhile, friendship quality has a moderating effect on the relationship between body dissatisfaction and social anxiety.

Authors' Contributions
Hui Xu and Qianqian Dou conceived the study and designed the trial, Ruosong Chang and Qianqian Dou supervised the conduct of the trial, data collection, provided statistical advice on study design and analyzed the data. Qianqian Dou drafted the manuscript, and all authors contributed substantially to its revision. Hui Xu took responsibility for the paper as a whole.
Funding No funding was received for conducting this study.

Data Availability
The datasets generated during and/or analyzed during the current study are available from the corresponding author on reasonable request.

Declarations
Informed Consent Informed consent was obtained from all individual participants included in the study.
Ethics Approval This study was approved and consented by the Ethics Committee of The School of psychology of Liaoning Normal University.

Conflict of Interest
The authors have no relevant financial or non-financial interests to disclose.