(boys cigarette use: F (2, 1200) = 3.60, p<.05, partial η2 =.01; alcohol use: 6.50, p<.01, partial η2 =.01; girls cigarette use: F (2, 1331) = 5.15, p<.01, partial η2 =.01; alcohol use: 8.77, p<.05, partial η2 =.01). Early maturing boys and girls had higher rates of cigarette and alcohol use than their late maturing peers. Early maturing girls also had higher rates of alcohol use than on-time maturing girls. Boys who matured on-time had higher rates of alcohol use than their late maturing peers. Examining whether levels of parent-child relationship quality differed across pubertal timing groups revealed that early maturing girls reported poorer relationship quality with their parents compared to on-time maturing girls at Time 1 (F (2, 1331) = 5.34, p<.01, partial η2 =.01) but not at Time 2 (F (2, 1331) = 1.02, p>.10, partial η2 =.00). No differences were observed for boys at Time 1 (F (2, 1200) = 2.69, p>.10, partial η2 =.00) or Time 2 (F (2, 1200) = 0.27, p>.10, partial η2 =.00).
