According to new research from The University of Texas at Austin and the University of Minnesota that was funded, in part, by a grant from the U.S. Army, bottling up emotions can make people more aggressive!
Using a pair of notorious movie scenes, the psychologists found that subjects who were told to not show emotions during the scenes were more aggressive later than those who were able to show their disgust.
They measured this by having the participants blast an imaginary person with sound, letting the participant pick the severity of the sound. The participants thought they were blasting a real person, and those who had to bottle up their emotions set the levels higher, on average, than those who didn't.
This isn't limited to movies. A real life example would be a worker who has to suppress anger towards a cruel boss. That worker might later be more aggressive to their friends or family.
Previous experiments have looked to find a link between aggression and sleep deprivation, and this study took a look at that too. They had groups who were told not to sleep for 24 hours before the study, while there was a group who were free to sleep. Unlike previous studies, this one found no link between sleep deprivation and aggression.
