Attentive tracking thresholds (+ SE) are shown as the total number of balls (i.e. the number tracked, plus distracters). Results for the two older groups only are shown, as very few of the RA group were able to complete the task. Little difference was shown in performance between the DD and any of the CA groups. Whilst the DD and CA [low IQ] groups performed equally, the CA [high IQ] group outperformed both groups indicating that nonverbal IQ rather than reading ability is a better predictor of performance. (* denotes significantly different from CA[high IQ] group, p < .05).