“Just think about it”? Cognitive complexity and moral choice

• Three studies find a curvilinear relationship between cognitive complexity and moral choice.
• The least ethical decisions use the lowest and highest levels of cognitive complexity.
• We both measure and manipulate cognitive complexity, and use two different ethical decisions.
• We suggest a way to reconcile conflicting findings about the role of reasoning in moral choice.
• We suggest we need to better account for both the moral benefits and dangers of cognitive complexity.

In this paper, we question the simplicity of the common prescription that more thinking leads to better moral choices. In three studies, we discover that the relationship between how complexly one reasons before making a decision with moral consequences is related to the outcome of that decision in a curvilinear way. Using two different moral decisions and both measuring and manipulating the level of cognitive complexity employed by the decision maker, we find that decisions made after reasoning with low and high levels of cognitive complexity are less moral than those made after reasoning at moderate levels of complexity. These results suggest that the best moral decisions are those that have been reasoned through “just enough”. Further, and at least as important, they illustrate the need to expand our study of ethical behavior beyond simple effects, and to gain a deeper understanding of the thought processes of individuals faced with moral choices.