Skill specificity, the notion that task performance is based on unique underlying information-processing components at skilled levels of performance, is examined from the perspective of the ability determinants of individual differences in task performance during skill acquisition. The current investigation uses a dynamic ability-skill theoretical perspective to evaluate how individual differences in procedural learning for a complex criterion task relate to learning of procedures for other more basic tasks such as choice and simple reaction time. An experiment with 86 college students was performed using a simulated Air Traffic Controller (ATC) task for assessment of procedural learning, along with practice on several perceptual speed measures and assessment of reference abilities. When subjects are allowed to practice tests of perceptual speed and psychomotor ability, some measures increase in their power to predict skilled performance on the complex ATC criterion task, a direct disconfirmation of the skill-specificity thesis. Discussion is devoted to the use of individual-differences approaches to address general transfer and skill specificity issues.