Hue discrimination thresholds (+ SE) for the identification of the "redder" of two bars are shown as the percentage difference. Better performance is indicated by a lower threshold. The DD and RA groups performed comparably, with both performing significantly worse than the CA group indicating that reading ability is a better predictor of performance on this task than age. The CA [high IQ] group clearly showed the best performance. Whilst the CA [low IQ] group showed marginally poorer performance, this group performed significantly better than both the DD and RA children, again indicating that reading ability rather than IQ is likely to contribute more to performance of this ventral stream task. (* denotes significantly different from CA group, p < .05; ^denotes significantly different from DD group, p < .05; ^^ p < .01).