Many factors influence the quality of decision making: importance, relevance, and even time of day can affect the degree to which we thoughtfully consider a decision. In a new IZA paper, Todd McElroy, David L. Dickinson and Nathan Stroh investigate how glucose, the brain’s fuel source for thinking, improves the quality and speed of decision making.
In an experiment, 138 glucose-deprived students were given a sugar drink or a placebo. After some time to allow glucose absorption, the participants had to complete a large set of decision-making tasks ranging from solving analytical problems to assessing social norms, risks, and own performance. The experimenters measured both response time and the quality of decisions.
The analysis shows that glucose enrichment did not improve decision making in the simpler decision tasks, but had a substantial effect on more complex decision making. Glucose-enriched participants also responded significantly faster to decisions than participants in the glucose-deprived condition.
These findings have many practical implications for future research and are especially relevant for technicians who make complex decisions that hinge on critically fast decision making. For example, consider air traffic controllers who must weigh multiple factors and make critical decisions quickly. The study suggests that both optimality and response time for this type of decision will be significantly affected by blood-glucose level.