title: Time of day, Intellectual Performance, and Behavioral Problems in Morning Versus Evening type Adolescents: Is there a Synchrony Effect?
abstract: We administered measures of fluid and crystallized intelligence to Morning- and Evening-type adolescents who were tested either during a morning session or an afternoon session, at times chosen to reflect the limits of the average school day schedule. For the fluid intelligence measures, there was a synchrony effect, with better performance at times that matched individuals' preferences. A composite measure of the subtests used (block design, digit span, and vocabulary) computed to a 6 point difference in IQ estimates. We also assessed the behavioral adjustment of these participants and found heightened levels of maladaptive behavior for Evening-type adolescents. Adolescents tested at their nonoptimal times of day and adolescents who are Evening-types appear to be at risk for poor academic performance and Evening-types appear to be at risk for behavioral adjustment problems.
authors.forename: David
authors.initials: D
authors.lastname: Goldstein
authors.forename: Constanze S
authors.initials: CS
authors.lastname: Hahn
authors.forename: Lynn
authors.initials: L
authors.lastname: Hasher
authors.forename: Ursula J
authors.initials: UJ
authors.lastname: Wiprzycka
authors.forename: Philip David
authors.initials: PD
authors.lastname: Zelazo