Effects of Practice on Speed of Information Processing in Children and Adults: Age Sensitivity and Age Invariance

In 2 experiments, children and adults were exposed to 4 different information-processing tasks. Consistent with the global trend hypothesis, age-sensitive linear relations were observed between child and adult latencies, and 10- and 11-year-olds were approximately 1.7 and 1.6 times slower than 19-year-olds as predicted by R. Kail's (1991) growth function. In Experiment 1, the relation between child and adult latencies did not change over 4 sessions of practice, implying that practice has equivalent effects on corresponding processing steps in children and adults. In both experiments, an age-invariant linear relation between dispersion and central tendency was observed, indicating that children's greater within-subject variability is entirely due to their slower speed of processing.