| Abstract: | Individuals seem to differ in their ability to maintain consistent performance. This is obviously an important attribute of behavior that has been largely neglected by researchers. There is, however, some evidence to suggest that, in certain types of situations, the behaviors of the mental retardate are characterized by a relatively high degree of variability. Two studies are reported here that deal with some of the developmental implications of intraindividual variability. In one study, involving retardates, reliability and generality of response consistency were examined in reaction time, time estimation, and digit span tasks. It was shown that individual differences in consistency are reliable and that these generalize across tasks. A second experiment was concerned with the developmental aspects of variability. First-, third-, and fifth-grade pupils and college students were given many trials on a reaction-time task. A variety of measures, reflecting typical performance, limit of performance, and variability, were computed for each subject. The ability to react quickly shows a developmental trend not only with respect to overall performance, but also in the efficiency with whichthe individual maintains his optimal level of responding. |
