Long-term learning trajectories evolve through microdevelopmental sequences (i.e., short-term processes of change during learning tasks) and depend on variability during and across learning tasks. The aim of this study is to examine the coupling between short-term teacher-student dynamics and students’ long-term learning trajectories, thereby providing empirical support for the link between the short- and long-term time scale in cognitive development. For 31 students (ages 3–5 years) from regular and special education, five teacher-student interactions during science tasks were filmed and coded in real time with regard to the student’s level of understanding and the teacher’s support throughout the task. A hierarchical cluster analysis resulted in four different learning trajectories over the course of 1.5 years, labeled as a high-scoring, mid-scoring, fluctuating, and low-scoring group of students. When connecting these trajectories to microdevelopmental data, the interactions of the high-scoring students were characterized by more moment-to-moment variations in the teacher’s support and student’s level of understanding, while the low-scoring group had the least variability compared to the other groups. Students with emotional and behavioral disabilities were represented across all learning trajectories, despite frequent accounts in the literature on their significant academic delays.

Although human societies provide protection from harm and enable the construction of collaborative and mutually beneficial social structures, they also pave the way for social hierarchies that deny equal treatment to certain portions of the population. Moral judgments about fairness and equality, as well as stereotypes, biases, and prejudice, emerge as early as 3 and 4 years of age. Investigating young children’s responses to the unfair treatment of others reveals that, beginning at 3–4 years of age, children often act on ingroup biases and do not yet challenge exclusion or rectify inequalities. By 5–6 years of age, however, children’s knowledge of groups, along with their understanding of others’ mental states, enables them to begin to critically evaluate unfair practices, particularly in peer contexts. These factors play a significant role in young children’s emerging ability to challenge unfair treatment of others.