Given that there was no Condition by Age Group interaction, we tested the effect of feedback, collapsed across condition. The Levene test (2, 88) = 2.97, p = .056, suggested the homogeneity of variance assumption was close to being violated within a linear contrast. Thus, we moved directly to post hoc pairwise tests. Comparisons with the 15–17-year-old group were tested with equal variances not assumed. The 10–12-year-old group had a more negative amplitude than the 15–17-year-old group, t(51.21) = −3.94, p = .0002. The 13–14-year-old group had a more negative amplitude than the 15–17-year-old group, t(38.88) = −2.56, p = .015. The 10–12-year-old group was comparable to the 13–14-year-old-group, t(66) = .064, p = .949. No other effects, including interactions, were significant, Fs < 1.0, ps > .05.
