Part of the reason is that the lower levels of our brains take over.
Higher level behavior, activities such as decision-making, memory and observational skills, which are controlled by the cerebral cortex, are usurped by a fast-acting part of the brain called the amygdala during a violent confrontation.
“It causes a shift in hormones, blood pressure, heart rate, it can even slow down digestion,” said Catherine Pittman, professor of psychology at St. Mary’s College in Notre Dame, Ind. “It’s really a lower level of your brain that takes charge.”
Pittman said the amygdala and cortex work simultaneously — one processing higher level functions and one preparing the body to escape or do battle.
“There are many levels of the brain that are operating [during a confrontation],” she said. “Some are operating under your control and some operate so quickly that you can’t control.”
The combination of fear and a weapon can lead to deadly consequences.
“If you feel in danger you don’t think rationally or logically,” Pittman said. “The problem is that a gun is an easy thing to operate. It just takes one movement of your finger. You can feel threatened and take an evasive action, or you could kill someone based on a perception that is not accurate.”