Selective Engagement of Cognitive Resources Fail to Account for Age-Related Positive Skew Bias

Many risky decisions in everyday life are skewed—that is, the risks and their associated outcomes are unevenly distributed. There is robust evidence that people tend to prefer ‘positively skewed’ choices, which have a small probability of a large gain coupled with a large probability of a small to moderate loss (e.g., a lottery ticket). Recent evidence suggests that the strength of this positive skew bias increases with age. In this preregistered study (https://osf.io/ugf6s/), we aimed to determine whether the age-related positive skew bias can be partially explained by the selective engagement of cognitive resources to avoid choices with larger potential losses (i.e., negatively skewed gambles). To test this, we manipulated cognitive control demands by introducing a time pressure manipulation during a decision making task. Because engaging in cognitive control takes time, particularly for older adults, limiting the decision window can reduce cognitive control. Participants (N = 78) made a series of choices between a certain, safe option (no winning or losing additional money), and an uncertain skewed option (chance of winning or losing money with some probability) with and without time pressure. If older adults selectively engage their cognitive resources during negatively skewed gambles to avoid large potential losses, we expected to see that under time pressure, there would be a reduction in the positive skew bias for older adults. We found that time pressure did not influence preference for skewed gambles, suggesting that the age-related positive skew bias cannot be accounted for by selective loss avoidance. However, we did replicate the previous findings of an age-related increase in positive skew bias in our sample, finding that with increased age, preference for positively skewed gambles increases while preference for negatively skewed gambles decreases.