Preschool teachers' perceptions about relationships with students (teacher–child relationships [TCRs]) predict children's subsequent social competence (SC) and academic progress. Why this is so remains unclear. Do TCRs shape children's development, or do child attributes influence both TCRs and subsequent development? Relations between TCRs and other measures were examined for 185 preschoolers (107 girls, 89 longitudinal, and ~75% European American). Teachers rated TCRs and child social/affective behaviors. Teacher–child interactions (TCIs) and children's affect expressiveness were observed. Child SC and receptive vocabulary were assessed. TCRs were significantly correlated with each type of outcome. TCIs, SC, expressed affect, and teacher‐rated behaviors also predicted TCRs longitudinally. Results suggest that TCR ratings predict subsequent adaptation because they summarize children's behavioral profiles rather than on TCR quality per se.