Motor performance and response consistency as a function of age

The specificity versus generality of motor performance and motor response consistency ws investigated as a function of age. 120 Ss, 30 each at age 7, 11, 15 and 19 yr., were given 120 practice trials (60 trials per session with 24 hr. interpolated between sessions) on both simple and choice RT tasks. For motor performance the reliability of individual differences were high in both tasks at all ages, while the amount of generality was moderately high in the two younger groups but diminished with age. The reliability coefficients for motor response consistency were low for both tasks but, with two exceptions, statistically significant. There was no evidences for generality in motor response consistency at any age.