Individual differences in skill acquisition are influenced by several architectural factors. According to Ackerman’s theory, general intelligence, speed of proceduralization and psychomotor speed influence different stages of skill acquisition. The ACT-R cognitive architecture allows for direct testing of this theory by manipulating parameters that correspond to these factors. The present study discusses an ACT-R model of the Kanfer–Ackerman Air Traffic Control task in which the relevant abilities can be manipulated directly. The model predictions show the same patterns of correlations as the patterns found by Ackerman in the experimental data.