Participants
Before conducting the survey, the research team underwent uniform training to ensure that the researchers followed scientific principles and were able to demonstrate a friendly attitude and efficient actions during the survey. The subjects were selected from five junior high schools in Hunan Province by random sampling. A total of 850 questionnaires were distributed, and 741 valid questionnaires were obtained, with an effective rate of 87.18%, including 328 boys(44.26%), 413 girls(55.74%), 246 in grade one(33.20%), 311 in grade two(41.97%), 184 in grade three(24.83%), and the age was13.82 ± 0.91.
Measures
Family cohesion and adaptability scale
This study used the Chinese version of the scale prepared by Olson, after being revised by Fei et al. The scale consists of 30 questions, divided into two dimensions, cohesion, and adaptability. There are 16 questions on cohesion, such as "In our family, we do all recreational activities together," and 14 questions on adaptability, such as "When conflicts arise in the family, the members make compromises with each other in a humble manner." A 5-point scale was used, with one definition "not", two definition "occasionally", three definition "sometimes", four definition "often ", and five definition "always". The higher the score, the better the family function [31]. In the present study, Cronbach’s alpha coefficient of the scale was 0.97.
School Belonging Scale
The Chinese version of the School Belonging Scale was prepared by Goodenow and revised by Pan Dafang et al. The scale has 18 items, divided into three dimensions, including a sense of belonging, identity, and school attachment, and has good reliability and validity. Among them, there are seven items for a sense of belonging, such as "The students at this school take my opinions seriously"; 8 items for identity, such as "The people at this school are friendly to me"; and three items for school attachment, such as "I can do what I want at this school". I can be my authentic self at this school". A 5-point scale was used, with one being "never like this", two being "slightly not like this", three being "average," four being "slightly like this," and five being "always like this" [32]. In the present study, Cronbach’s alpha coefficient of the scale was 0.95.
Adolescent Student Self-support Personality Inventory
The Self-support Personality Inventory for Adolescent Students developed by Xia et al. was used, which consists of two subscales, the Personal Self-support Scale and the Interpersonal Self-support Scale, each with 20 items [33]. For example, the question of personal independence, "Likes to arrange things to be done in advance", and the question of interpersonal independence, "Usually afraid to go to someone's house alone". The scale is scored on a 5-point scale, with higher scores indicating higher levels of the trait in question [34]. In the present study, Cronbach’s alpha coefficient of the scale was 0.87.
Self-esteem scale
The self-esteem scale was revised by Yang et al. on the self-esteem scale developed by Rosenberg [35]. There are ten items (items 3, 5, 9, and 10 are reverse scoring, due to cultural differences between China and the West, question 8 was changed to positive scoring). The scale is scored on a 4-point scale (one point for "very nonconforming", two points for "nonconforming", three points for "conforming", and four points for "very conforming"). For example, the question item, "I feel that I am a valuable person, at least on the same level as others". The higher the total score obtained for the scale, the higher the level of self-esteem.
Data analysis
The study used SPSS 22.0 to analyze the data, starting with descriptive statistical analysis, followed by correlation analysis, and then testing for mediating effects of self-support and self-esteem. The Hayes (2013) PROCESS macro (Model 6) was evaluated during the chain mediation model examination. Bootstrap procedures were conducted to test the chain mediation model. Five thousand bootstrap resamples were set to calculate the 95% confidence intervals of the indirect effects in all statistical analyses. In the data analysis, the respondents’ gender, grade, and age were used as control variables.