The use of IQ assessment in astronaut screening and evaluation

Background: The screening and evaluation of astronaut candidates usually includes measures of cognitive and intellectual capacity. Questions of ceiling effects and discriminability when evaluating individuals assumed to be of above average intelligence should be considered. The current study examines ceiling effects and discriminability on IQ assessment between pilot vs. mission specialists and men vs. women in the selection of astronaut candidates. Methods: IQ scores on 104 male and female Shuttle astronaut candidates as measured by the Multidimensional Aptitude Battery (MAB) were analyzed via factor analyses and tests of differences between genders, selection status, and job types. Total group, gender, and job type specificity and sensitivity and overall percent correctly classified were assessed on selected vs. unselected classification. Results: Exploratory and confirmatory factor analyses failed to replicate the proposed factor configuration prompting reconfigured domain scores. Analyses of differences between gender, selection, and job categories found different results when using reconfigured IQ scores compared to the original formulation. The 10 subscales performed better than overall domain scores in sensitivity, specificity, and as significant predictors of individuals selected. Both versions of Verbal, Performance, and Full Scale IQ scores performed similarly regarding sensitivity and specificity. The reconfigured scores were better predictors of selection. Discussion: Evidence for sensitivity, specificity, and classification prediction was better for subscales than overall domain scores. Some consideration to using reconfigured domain scores should be given to increase instrument utility.