A single study has documented a relationship between the age of an adolescent's mother at her first birth and the adolescent's levels of school engagement. Examining a national sample, Levine, Pollack, and Comfort (2001) found that adolescents whose mothers gave birth to their first child under the age of 20 were more likely to be truant than adolescents whose mother gave birth to their first child at a later age. This relationship was found even after controlling for key variables that might distinguish between mothers who give birth to their first child at earlier and later ages, such as the mother's level of education, household structure while growing up, and level of intelligence. Yet, this study did not control for other important characteristics that might be related to the age at which an adolescent's mother first gave birth and adolescents' educational adjustment, such as parenting quality. Clearly, more research is needed to determine whether Levine et al.'s (2001) finding is found in different samples and using different methodology.