The Abecedarian project offers some additional evidence from a randomizedtrial with a sample of 104 at age 21 follow-up. The Abecedarian Preschool Project provided low-incomeAfrican-American children with full-day educational child care from birth to age 5, and has demonstratedimportant long-term benefits for children such as higher rates of high school graduation and collegeattendance. However, in an early study, teachers rated 59 children from the project to be more aggressiveduring the first three years of primary school than control group children. Although the teachers didnot dislike or find the Abecedarian children harder to manage than children from the control group, theAbecedarian children were more likely to kick, push, and hit in a variety of settings (such as lunchroomand classroom) than children from the control group. By the third year in public school, the aggressionlevel of students who had participated in the Abecedarian program began to decline, and the level forchildren in the control group began to rise slightly.There were no differences in aggressive behavior among children in the Abecedarian control group,although their exposure to child care ranged from none at all to nearly five years. Of course, the samplesize is quite small making it difficult to detect small effects. The study’s author suggests that the program’scurriculum was an important factor in explaining the difference between treatment and control groupaggression. In the early years of Abecedarian, the program emphasized academic growth in its curriculumactivities. When early results showing elevated aggressive behavior were observed, the program’s designerschanged the curriculum to reinforce prosocial alternatives, and they brought in a consultant to work withteachers on methods of behavior control. Subsequent cohorts of children enrolled in the program showedmuch lower rates of aggressive behavior. It is noteworthy that large positive effects on school success werefound across all cohorts.
December 19, 2011