Robustness of Decision-Making Competence: Evidence from Two Measures and an 11-Year Longitudinal Study

Decision-making competence (DMC) is the ability to follow normative principles when making decisions. In a longitudinal analysis, we examine the robustness of DMC over time, as measured by two batteries of paper-and-pencil tasks. Participants completed the youth version (Y-DMC) at age 19 and/or the adult version (A-DMC) 11 years later at age 30, as part of a larger longitudinal study. Both measures are composed of tasks adapted from ones used in experimental studies of decision-making skills. Results supported the robustness of these measures and the usefulness of the construct. Response patterns for Y-DMC were similar to those observed with a smaller initial sample drawn from the same population. Response patterns for A-DMC were similar to those observed with an earlier community sample. Y-DMC and A-DMC were significantly correlated, for participants who completed both measures, 11 years apart, even after controlling for measures of cognitive ability. Nomological validity was observed in correlations of scores on both tests with measures of cognitive ability, cognitive style, and environmental factors with predicted relationships to DMC, including household socioeconomic status, neighborhood disadvantage, and paternal substance abuse. Higher Y-DMC and A-DMC scores were also associated with lower rates of potentially risky and antisocial behaviors, including adolescent delinquency, cannabis use, and early sexual behavior. Thus, the Y-DMC and A-DMCmeasures appear to capture a relatively stable, measurable construct that increases with supportive environmental factors and is associated with constructive behaviors. Copyright © 2017 John Wiley & Sons, Ltd. Additional Supporting Information may be found online in the supporting information tab for this article. key words decision-making competence; adolescents; life span; individual differences Day to day, we make decisions that range from the relatively trivial to ones with major effects on our lives. Traditionally, normative theories of decision making have posited how people should make decisions that maximize the expected utility of their outcomes (e.g., Bernoulli, 1954; von Neumann & Morgenstern, 1953; Simon, 1978). Descriptive research in behavioral decision making has long focused on identifying when and why individuals systematically deviate from the principles posited by traditional normative theories, and on the efficiency of the heuristic strategies that sometimes replace them (e.g., Einhorn & Hogarth, 1981; Hastie & Dawes, 2010; Kahneman, Slovic, & Tversky, 1982). For example, people may violate the normative “sunk cost” principle by continuing to invest in unprofitable options, especially when they have made large unrecoverable investments (Arkes & Blumer, 1985). People may also violate the traditional normative principle of “description invariance,” as when they rate a team as more successful when described in terms of its 60% success rate rather than its 40% failure rate (Dunegan, 1993), perhaps reflecting conversational norms that prescribe using success rates to describe successful teams and failure rates to describe failing ones (Sher &