Specificity versus generality of motor response consistency.
The hypothesis that tasks are specific and not based upon general underlying factors (specificity hypothesis) was tested for motor response consistency, or intra-individual variability, SD(intra). Four motor tasks involving rapid speed of movement were administered to 46 Ss. The reliability of SD(intra) ranged from .45 to .78 indicating that there are reliable individual differences in SD(intra) and that inconsistency is not simply random error. Also, the reliability of SD(intra) increased as the number of trials/S increased. Even though the mean score correlations indicated a moderate degree of generality, inter-correlations among tasks using response consistency scores were very low indicating specificity of response consistency.