Cognitive ability and non-cognitive ability are two important dimensions of human capital ability. With the increasing competition in education, families, schools, and teachers mainly pay special attention to children’s cognitive ability but neglect non-cognitive ability. However, non-cognitive ability is an important ability that affects the life of children. Schools, especially teachers, play a unique role in the development of children’s physical and mental health. Therefore, the role of teachers in “educating children” is very important in the process of the cultivation of non-cognitive ability, and the accumulation of children’s “human capital” will not only affect their future performance in the labor market, but also accelerate the construction of a talent-powerful nation.

Since non-cognitive ability is highly malleable in childhood, this paper uses the data from 2013−2014 China Education Panel Study (CEPS) to estimate the impact of teachers’ behaviors, measured by their emotional support and information feedback on children’s non-cognitive ability. It also deals with the endogeneity of teachers’ supportive behaviors caused by omitted variables and reverse causality. We find that teachers’ emotional support can improve children’s agreeableness and extraversion by helping children make more friends, and teachers’ information feedback behaviors can improve children’s conscientiousness and openness by causing parents to pay more attention to children’s study. In addition, teachers’ emotional support improves the social ability and prosocial behavior of disadvantaged children, such as rural, left-behind, and migrant children. A series of robustness checks further strengthen the conclusions.

The contributions are as follows: First, previous literature mainly focuses on the individual characteristics or added value of teachers, while this paper investigates the impact of teachers on children from the perspective of behavior. Second, based on the existing literature, this paper uses a variety of methods to overcome the endogeneity caused by omitted variables and reverse causality and obtain the causal effect of teachers’ behaviors on children’s non-cognitive ability. After re-estimating with instrumental variables constructed by whether teachers’ gender and children’s gender are the same, we confirm that the impact of teacher’s gender on children’s non-cognitive ability in previous studies is generated through teachers’ higher supportive behaviors for children of the same sex.

This paper provides policy implications for cultivating children’s human capital and improving the non-cognitive ability of disadvantaged children from the perspective of school, and also provides some inspiration for family education. Therefore, education policy-makers and managers should pay attention to improving teachers’ supportive behaviors, so as to promote the healthy growth of children, provide inexhaustible power for the sustainable development of China, and accelerate the construction of a talent-powerful nation.