Objective: To explore the development trajectory of coping strategy and gender difference during childhood. Methods: A total of 355 children in grade 3 from 2 primary schools in Zhongshan of Guangdong Province and Dazhou of Sichuan Province were assessed with cooping strategy and followed up for 2 years. Results: Positive and negative coping strategies have different developmental trajectories during childhood, with non-linear upward trend in positive coping strategies (eta11=0.11, 0.02, P>0.05) and non-linear downward trend in negative coping strategies (eta12=-0.70, -0.08, P<0.01). The development of positive coping strategies during childhood showed no significant gender difference (△χ2=5.19, df=4, P>0.05). While the initial average negative coping strategies was significant higher in boys(β=-0.56, P<0.01), and the decreasing velocity was faster than the girls(β=0.33, P<0.01). Conclusion The coping strategy during childhood shows great plasticity, with positive and negative coping strategy develops in different trajectory. The developmental trajectories of negative coping strategies during childhood illustrate significant sex difference, while it is not the case for positive coping strategy.

Objective: To explore the development of children’s loneliness and their gender differences, and to provide references for elementary school students’ mental health education. Methods: The Children’s Loneliness Scale was being used in this research. 771 students in grade 3 and 4 were investigated and followed for 2 years, a total of 5 waves of data were collected. Results: The scores of pupils s loneliness in 5 times were(33.96±12.77)(31.13±12.82)(29.66±12.65)(28.67±11.97)(27.60±11.63) respectively. Feelings of loneliness decline rapidly in mid-childhood(eta1=-2.61, P<0.01), but in late childhood, it showed a significant upward trend(eta2=0.27, P<0.01). In the middle and late childhood, the level of loneliness of boys was significantly higher than that of girls at different points in time. But there was no significant gender difference in the pace of loneliness during childhood(β1=0.06, β2=0.01, P>0.05). Conclusion Childhood loneliness presents non-linear curve,decreasing with age during early childhood, but tends to increase in later childhood.

Objective: To analyze the status of childhood bullying bystander s behaviors among pupils and the correlation with family function,so as to provide empirical support for educational intervention in campus bullying. Methods: A questionnaire survey using the cluster random sampling method was administered to 1 145 pupils from a primary school in Wushan County within Chongqing City in November 2019, including Pupil Bullying Bystander Behavior Scale and Family Adaptability and Cohesion Evaluation Scale(FACES). The χ 2 test, Spearman related analysis and binary Logistic regression were used to determine the detection rate of different bullying bystander behaviors among pupils and the association with family function. Results: The proportion of bullying promoters, bullying protectors, and bystanders were 4.7%, 92.1%, and 42.1%, respectively. There were statistically significant differences in the three types of bullying bystander s behaviors among the different grades pupils( χ 2=21.45, 7.98, 27.48, P < 0.05 ). There were significant correlation between family function and its dimensions with different types of bullying bystander behavior ( | r |= 0.07-0.20, P <0.05). Binary Logistic regression analysis showed that pupils family function and grade had statistically significant impact on promoting bullying behavior, protecting victim behavior, and bystander behavior ( OR =0.98, 3.33; 1.02, 1.95 ; 0.99, 0.58, 0.41, 0.61, P <0.05). Conclusions The bullying bystanders behaviors of pupils are related to grade in school and family function. Schools should implement educational interventions for pupils of different grades and focus on improving pupils family function to effectively promote the occurrence of positive bystanders behaviors in pupils.