There are large differences in expulsions and suspensions on the basis of race starting in preschool and divergent explanations for their cause. The current study explores how developmental methodology can shed light on this vexing issue. We leverage two measures: (1) childcare provider complaints about children's behavior and their recommended disciplinary action (measured by parent report); and (2) observed disruptive behavior measured by a laboratory-based standardized observation tool, the Disruptive Behavior Diagnostic Observation Schedule (DB-DOS), among a large, sociodemographically diverse sample of children (n = 430; mean age = 4.79 years). We identified three latent class profiles on the basis of race/socioeconomic status (SES) and found disparities in childcare provider complaints based on profile membership. More specifically, children classified in the "Black/Hispanic, poor" and "Black, nonpoor" profiles both had significantly higher childcare provider complaints compared with children in the "White/Hispanic, nonpoor" profile. By contrast, there were no differences in observed disruptive behavior based on race/SES profiles. Finally, childcare provider complaints in preschool were associated with lower cognitive performance in elementary school, above and beyond observed disruptive behavior in preschool and race/SES profiles. Implications for classroom practice and contributions to the national debate on school disciplinary policies are discussed. [This paper was published in "Annals of the New York Academy of Sciences" v1508 n1 p123-136 2022.]