Investment theory and tilt: Evidence from jobs and job families

Cattell's (1987) investment theory states that individuals make choices to “invest” their cognitive ability in some areas but not in others. The theory suggests that individuals should gravitate to training and occupations that align with their investments. To test this theory, scores reflecting academic ability (ACAD) and technical knowledge (TECH) were derived from the Armed Services Vocational Aptitude Battery for a large sample of United States Air Force enlistees. The ACAD and TECH scores were used to create an index of ACAD-TECH tilt. Analyses were performed separately for 19 training courses with a technical knowledge requirement (mechanical or electronic) and 34 courses with no technical knowledge requirement. Consistent with investment theory, most of the technical training courses (63 %) had a technical tilt (TECH > ACAD), whereas most of the non-technical training courses (88 %) had an academic tilt (ACAD > TECH). ACAD had the strongest correlation with training grades for both the technical (r = 0.386) and non-technical (r = 0.318) courses. Tilt demonstrated weaker correlations with training grades than either ACAD or TECH for both the technical and non-technical courses. Final School Grade (FSG) was regressed on ACAD, TECH, and Sex. Similar results were observed for all courses, technical courses only, and non-technical courses only. ACAD was significantly correlated with FSG, with little incremental validity for either TECH (Δ r from 0.000 to 0.010) or the contribution of TECH and Sex (Δ r from 0.001 to 0.012).