Why do humans dissociate during traumatic happenings?

People may feel an unanticipated surge of emotional numbness during stressful situations, or they may feel as though they are experiencing an out-of-body experience and have divorced from reality. 

Dissociation, a defence mechanism that isolates potentially dangerous thoughts and emotions from the rest of a person's psyche, is characterised by these symptoms of detachment. However, why do our minds occasionally detach from traumatic experiences?

Notably, dissociation can be helpful in circumstances where an individual is unable to physically flee stress or danger, like when they are the victim of abuse or a violent crime, according to Steven Dubovsky, an emeritus professor of psychiatry at the University of Buffalo in New York.

The sympathetic nervous system, which is in charge of our "fight or flight" reaction, normally kicks in when someone is in immediate danger. This response is an evolutionary adaptation shared by all mammals, including humans, and forces them to fight or run from danger in order to survive. 

Another way the nervous system is prepared to react to trauma is through dissociation, which happens when fighting or fleeing seems too risky or unfeasible. 

Dubovsky outlined a scenario in which an individual on a dark street could be pursued and attacked by a group of people. A person may become trapped in the circumstance if they are unable to fight back or discover a way out.

"When the stressful thing is something you can't escape from, you're going to have trouble functioning unless you can turn [the fear] down," he told Live Science.

Dissociation is a protective mechanism that allows a person to mentally distance himself from a circumstance that is causing them pain—either physical, emotional, or both. 

A 2017 study published in the journal Current Psychiatry Reports suggests that this coping mechanism may also involve freezing and distancing oneself from memories of the traumatic incident. 

According to a 2015 study published in the journal Medicine, victims of abuse or sexual assault frequently report experiencing dissociation during the incident. Some people claim that dissociation causes them to have hazy memories of an event after it has happened. 

Dissociation can prevent someone from having to cope with traumatic recollections, even though the absence of a distinct recall or a sense of attachment may be startling, according to Dubovsky.