YASUNARI RAMON SUAREZ TAGUCHI February 20, 2023

Sleep has long been earmarked to be an essential in life – a biological need which a lack of can impair performance, reduce alertness and have adverse effects on one’s judgement, motivation, work efficiency and attention span.

Titled “Effect of subjective sleep quality on aggression: A two-year longitudinal and fMRI pilot study”, the study basically found a probable link between poor sleeping habits and aggressive behavior.

It was published in the Biological Psychology journal, and was conducted by researchers affiliated with the Sleep and NeuroImage Center at the Southwest University in China, who obtained data from an ongoing study with students from Chongqing, China called the Behavioral Brain Research Project of Chinese Personality. In their study, the researchers analyzed data from around four hundred and fifty students aged between sixteen and twenty six years old. The focused their analysis on data collected from two time points which were separated by a two-year span.

At both “collection points”, the students underwent assessments on the quality of sleep that they’ve been having in the past month, tests on their aggression levels which included sub-dimension tests on hostility, anger, physical aggression and impulsiveness, and also underwent a functional magnetic resonance imaging (fMRI) test to measure their brain activity.

The researchers then compared the students’ sleep and aggression scores with fMRI measurements of their spontaneous brain activity, and found that poor sleeping habits and aggression had ties to weaker activity in the limbic or frontal brain regions.

They also found that poor sleep quality and higher aggression were linked to stronger activity in the left and right dorsolateral prefrontal cortex, which is an area in the brain that’s implicated in emotion regulation.

Its Implications

Researchers Haobo Zhang and Xu Lei, the proponents of the study, note that their findings suggests that poor sleep quality can lead to deficits in emotional cognition, apart from cause higher than normal aggression levels.

The postulate that that reason for this is that lack of proper sleep makes people interpret the behaviors of others in a negative light, which leads them to exhibit more aggressive or hostile behaviors towards others.

As the study reveals evidence of a causal relationship between poor sleep quality and aggression, it adds and builds up on the current body of research devoted to the matter, and ultimately adds one more reason why a good night’s sleep is important.