Yale researchers discover why having an argument is so mentally exhausting

Few endeavors can be quite as mentally draining as attempting to change someone’s mind. Have you ever walked away from a heated argument or debate and find yourself mentally exhausted? It’s a common feeling after contentious discussions, and now a new study from Yale University has uncovered the neurological processes behind this phenomenon.

The short explanation is that disagreeing requires more mental energy and the activation of far more neural areas associated with higher cognitive functions than agreeing. In comparison, when two people agree their minds only activate a much smaller portion of sensory brain areas.

The long answer is a bit more nuanced. Researchers say the human mind is like an interactive social processor; in other words, when two people agree their brains actually link up to a certain degree, displaying “a calm synchronicity of activity.” Conversely, when disputes or disagreements arise, several different emotional and cognitive resources activate.

To illustrate this point, the study authors use the example of a large symphony orchestra filled with various instruments versus a musical duet. When two minds are in agreement, they play off of and complement each other like a duet, but in the heat of debate, the brain will activate far more neural areas (instruments) in an effort to win the argument.

“Our entire brain is a social processing network,” says senior study author Joy Hirsch, the Elizabeth Mears and House Jameson Professor of Psychiatry and professor of comparative medicine and neuroscience, in a release. “However, it just takes a lot more brain real estate to disagree than to agree.”

“There is a synchronicity between the brains when we agree,” Professor Hirsch adds. “But when we disagree, the neural coupling disconnects.” 

These findings were made possible thanks to a new technique Yale researchers developed allowing them to view the brain activity of two people in real-time as they engage in a conversation.

In collaboration with researchers from University College London, study authors gathered a group of 38 adults and surveyed them on many political/societal beliefs ranging from thoughts on same-sex marriage to marijuana legalization. Then, based on those responses, subjects were paired together and asked to discuss those issues in a face-to-face setting. Some pairs consisted of two people who expressed similar beliefs, while other pairs held opposing opinions.

As participants conversed, researchers utilized an imaging technology known as functional near-infrared spectroscopy to observe brain activity during the discussions.

Most brain activity during harmonious discussions occurred in the sensory areas of the mind, such as the visual system. Researchers say this is likely because we tend to look for social cues from other people while engaged in normal conversation. During debates, however, those brain regions were much less active. Instead, the brain’s frontal lobes, responsible for higher-order executive functions, took center stage during arguments.

The mind certainly isn’t alone when it comes to extra energy spent during tense moments and arguments. We all know that heated debates can raise blood pressure, cause stress to skyrocket, and often leads to lost tempers. Across many areas, it takes a whole lot more work for our bodies to be agitated than relaxed. 

The full study can be found here, published in Frontiers in Human Neuroscience.