Behaviors of 504 middle-class children at 1 year of age and their mothers were assessed with descriptive checklists. Many typical stage-related behaviors led to parental concern or frequent parentchild conflict; 24% of the mothers identified at least one conflict area and 42% expressed concern about at least one aspect of their children's behaviors. Approximately 13% of the mothers thought their children were very or moderately difficult to rear, and about 6% thought their children had behavioral or emotional problems. The mothers reported considerable variation in the number and type of cognitively stimulating activities that they engaged in with their children. The implications of these findings for well-child care are discussed.