Humans possess a tendency to rapidly and consistently make character evaluations from mere facial appearance. Recent work shows that this tendency emerges surprisingly early: children as young as 3-years-old provide adult-like assessments of others on character attributes such as “nice,” “strong,” and “smart” based only on subtle variations in targets’ face shape and physiognomy (i.e., latent face-traits). The present research examined the behavioral consequences of children’s face-trait judgments by asking whether, and if so when in development, the appearance of face-traits also (a) shapes children’s judgments of targets’ behaviors and (b) guides children’s behavior toward targets. Experiments 1 and 2 showed that, by 3 years of age, children used facial features in character evaluations but not in judgments of targets’ behavior, whereas by 5 years of age, children reliably made both character and behavior judgments from face-traits. Age-related change in behavior judgments was also observed in children’s own behaviors toward targets: Experiments 3 and 4 showed that, by age 5 (but not earlier), children were more likely to give gifts to targets with trustworthy and submissive-looking faces (Experiment 3) and showed concordance between their character evaluations and gift-giving behaviors (Experiment 4). These findings newly suggest that, although children may rapidly make character evaluations from face-trait appearance, predicting and performing social behaviors based on face-traits may require more developed and specific understanding of traits and their relationships to behaviors. Nevertheless, by kindergarten, even relatively arbitrary and subtle face-traits appear to have meaningful consequences in shaping children’s social judgments and interactions.