This article examines whether the idea of "temperament" is a useful construct for families to understand babies' and toddlers' behavior. The author suggests that "regulatory skill" may be a more neutral term than temperament for parents and practitioners to use in discussing individual differences among babies and toddlers and suggests that temperament could be thought of as a classification of regulatory skill. Blackwell emphasizes the need for flexibility in using this construct, as definitions of temperament vary across cultures. The author provides five guidelines for using the construct of temperament as an effective clinical tool with parents of fussy babies.