Decision-making in people with mild intellectual disability: Relations with intelligence and a measure of executive functioning

ABSTRACT Background In this study we aimed to explore how intelligence and executive functioning are related to decision-making regarding social situations in persons with mild ID. Method We studied 80 vocational school students with mild ID; the controls were 80 students of a similar age. We assessed decision-making ability with the Important Life Decisions Task. Intelligence was assessed with the Wechsler Adult Intelligence Scale – Revised (WAIS-R), and executive functioning with the Wisconsin Card Sorting Test (WCST). Results The WAIS-R Verbal Comprehension and the Memory/Freedom From Distractibility factors predicted the decision-making score. Executive functioning was not related to decision-making. There was no interaction between the group and other variables. Conclusions Verbal intellectual abilities and abilities related to short-term memory and attention play an important role in decision-making regarding social situations. The difference in performance between persons with ID and the control group should be regarded as quantitative and not qualitative.