Short-term memory may be even more important than we thought.

While intelligence plays a crucial role in the ability to gauge short- and long-term benefits and resist temptations, scientists have, until recently, been unsure of why this connection between intellect and self-control exists. But a study released Tuesday by Yale assistant professor of psychology Jeremy Gray and a team of researchers concluded that working, or short-term, memory may be part of the missing link between goal management and higher intelligence.

The study is built on the widely-accepted theory that a specific physical location in the brain — known as the anterior prefrontal cortex — functions in tasks related to both complex reasoning and self-control, Colin de Young, former Yale psychology researcher and co-author of the study, said. The team sought to analyze the correlation between self-control and intelligence “at a more mechanistic level,” he said.

“[The results] showed that brain activity that predicted how well someone does on working memory tests is explained by the association between intelligence and self-control,” de Young said.

The researchers tested the responses of 103 participants to three categories of tests measuring working memory, intelligence and self-control. The participants underwent simultaneous functional magnetic resonance imaging (fMRI) tests to pinpoint the area of the brain experiencing the most activity, the authors said. Statistically, de Young said the results showed that those who displayed higher intelligence were better able to resist the temptations of short-term benefits. Those who were more capable of delaying gratification consistently showed higher activity in brain areas that are known to control working memory, he said.

The results of the study indicate that exercises aimed at improving a person’s complex-reasoning skills might help increase self-control, and vice versa, Gray said. The study may also influence the way in which physicians treat addiction in patients, he said.

But despite the fact that intelligence and the ability to resist temptation are linked, Gray said, even highly intelligent people are often victims of addiction and poor decision-making.

“Everyone is pretty much susceptible,” explained Gray, “but some people might be able to resist, or better yet, might be able to avoid temptation in the first place.”

The study indicates that people who can easily resist temptation possess a type of “deep intellect” that allows them to integrate seemingly unrelated information in order to weigh the consequences of their actions, Adam Green, co-author and a postdoctoral researcher in the Department of Psychology, said.

Gray is now looking to conduct a follow-up study in which he aims to sever this connection between self-control and intelligence. He said he plans to explore a certain genetic variant of dopamine D4 receptor that he believes will “uncouple” the two characteristics. This experimentation might uncover new opportunities for clinical treatment, potentially allowing reasoning abilities to increase even if people are still impulsive, Gray said.