This study hypothesized that (1) inmates functioning at low levels of academic achievement have a potential for effective cognitive performance not apparent in their low academic achievement; (2) the potential for effective cognitive performance will be demonstrated on the LPAD tests in the form of a significant improvement in performance from pretest to posttest as a result of teaching and intervention; and (3) the level of cognitive ability achieved by a low academic achievement group as a result of training will not be significantly lower than the pretest level of performance demonstrated by high achievers. The research, which was conducted in two major Federal Canadian penitentiaries, involved two groups at each institution: a group with an academic achievement level of grade 8 or above and one with an achievement level of grade 5 or below. Three LAPD assessment instruments were used to measure cognitive modifiability, i.e., the extent to which an individual's approach to learning and the effectiveness of his/her learning can be modified by experience. This involves a pretraining test, training, and a posttraining test process. The study demonstrated that low achieving inmates can learn to perform complicated cognitive tasks with short-term instruction and training. Also, the low-functioning inmates were able to solve complex problems with the same efficiency and sophistication as members in the high-achieving groups. Findings suggest that failure to learn in the past is not indicative of an inability to learn. Forty-two references are provided.