Physical Maturation and Information-Processing Speed in Middle Childhood

Because developmental increases in processing speed may have a maturational basis, individual differences in physical maturation were hypothesized to be associated with information-processing speed. Physical maturity was estimated for 134 9- and 10-year-olds using relative stature (RS), the percentage of estimated adult height each had attained. Thirty children in the most mature RS quartile and 30 in the least mature quartile completed 3 reaction time tasks used by S. Hale (1990) . There was an overall tendency for early maturers to be faster than late maturers, although this maturity effect was primarily the result of a significant effect for boys. The early maturers' faster processing times may be specific to boys or to a specific range of physical maturities.