If a person were confronted with a very dangerous situation, why might their sympathetic nervous system NOT engage?

• A. Because the parasympathetic nervous system is easier to engage.
• B. Because their brain thinks there is no chance of survival.
• C. Because the sympathetic nervous system had already been engaged earlier that day.
• D. In dangerous situations, the sympathetic nervous system always engages.

Answer: (B)

The key idea is that the body’s emergency response isn’t automatically “fight or flight” in every dangerous moment. In some extreme or overwhelming threats, the brain may determine there’s little or no chance of survival, and the appropriate response can be to freeze or dissociate rather than mobilize energy for action. When that appraisal happens, sympathetic activation can be reduced or delayed, and a parasympathetic-dominated response can take over, sometimes leading to fainting or immobility. This explains why someone might confront a dangerous situation and not exhibit the typical sympathetic arousal.

So, the brain’s judgment about survival likelihood can suppress the usual sympathetic engagement, producing a freeze-type reaction rather than active fight or flight. The other ideas don’t fit as well: the notion that the parasympathetic system is simply easier to engage isn’t a universal rule, past sympathetic activation doesn’t determine current response, and the idea that the sympathetic system always engages in danger ignores the well-documented freeze and dissociative responses.