Does need for relatedness matter more? The dynamic mechanism between teacher support and need satisfaction in explaining Chinese school children's regulatory styles

Grounded in the basic psychological need theory (BPNT) and the relationships motivation theory (RMT), this study investigated 1) the dynamic mechanism between teacher support (i.e., autonomy support, structure, and involvement) and need satisfaction (i.e., needs for autonomy, competence, and relatedness) in relation to regulatory styles (i.e., external, introjected, identified regulations and intrinsic motivation) among Chinese elementary school students; 2) the unique involvement-need for relatedness link to regulatory styles; and 3) the equivalence of the above investigations across lower- and upper-grade elementary students. We found: 1) the involvement → need satisfaction → regulatory styles paths to be aligned with the universality claim of BPNT and complementary function of need support in satisfying psychological needs for all the students; 2) the uniqueness of relatedness to be aligned with RMT for all the students; 3) the invariance across the lower- and upper-grade students in most of the direct and indirect paths, except that 4) the autonomy support → need satisfaction → autonomous regulation paths benefited more for upper-grade students.