The benefits of participating in the Abecedarian Project remained evident 15 years after the end of the program, as illustrated in this graph of the mathematics achievement of children who participated either in the program or in the control condition. Relative to the average level of mathematics achievement of children in the United States, performance of both groups of children declined somewhat between ages 8 and 21, but at all ages, children who participated in the program performed better than did children from comparably disadvantaged backgrounds who had been in the control condition.