This study investigated students' metacognitive and intellectual development within the context of academic training, achievement, and personality type, using two longitudinal data sets from a four-year public institution. The first set included 408 male students of the 1996 cohort; the second was comprised of 419 male students of the class of 1997. The two cohorts were measured on three occasions: freshman matriculation, end of sophomore year, and immediately prior to graduation. Results of the study indicated that: (1) metacognitive development unfolds in a discontinuous pattern during the undergraduate years; (2) metacognition varies with academic training, with engineering students demonstrating a higher degree of metacognition than liberal arts majors, and science students outperforming engineering and liberal arts majors on problem solving; (3) metacognitive and intellectual development are fostered by academic achievement; students with higher grade point averages are less dependent on external forces for thinking and experience less uncertainty; (4) students become less absolute in thinking and less dependent on external forces as they progress through college; (5) students demonstrate increased confidence in their belief systems as they shift from a preference for clear-cut thinking to an understanding that events can be viewed from multiple perspectives; and (6) intellectual development varies with personality type. (Contains 34 references.) (CH)