The moment your body perceives a threat, the brain undergoes striking changes.
Communication breaks down between the prefrontal cortex, where rational thought and judgment reside, and the amygdala, where fear rules the day. Your brain gets pumped up on hormones like testosterone and noradrenalin and epinephrine. It’s the latter two that pack the real emotional punch. But they also make you more focused and alert in response to the threat.
You’ve probably experienced the surge of energy known as an adrenaline rush. This surge helps mobilize your muscles as it temporarily sharpens your senses and enhances certain types of memory.
As this automatic, instinctual response continues, your pupils dilate, your heart speeds up, your breathing becomes rapid and shallow, your digestion slows, and your perspiration increases. Your brain even becomes deprived of blood and oxy- gen as those precious resources are rushed directly to your large muscles so you’ll be ready to move fast if you need to. You’ll also be feeling especially sure of being in the right, and you’ll be powerfully convinced that it’s important for you to do something right now. And so it starts—the blaming, the arguing, the yelling, the hitting . . . the list goes on. After all, how can you think clearly when your brain is starving for blood and oxygen? Your rational mind is no match for your body’s fight-or-flight response, and it will take you a full 20 minutes to calm down phys- ically and psychologically even after the response has stopped.
There’s nothing more urgent than danger, and as far as your body is concerned, you’re back in the same neck of the woods where one of your ancient forebears was devoured by a predator capable of extinguishing the entire human species. Your fight-or-flight response tells you that you’re facing a potentially fatal threat, that you must kill it or run away from it as fast as you can, and that you must not allow this threat to come anywhere near you ever again.
The fight-or-flight response is useful in the short term—it tells you that some- thing is wrong, it opens your eyes to the situation around you, and it focuses your attention on what needs to be changed. But it’s an emergency response, a state of high arousal that your body isn’t built to maintain for very long. When this response endures over time, as it does when you’re in a chronic state of anger, your body starts to break down. Then the same physiological changes that are meant to help you in an emergency start to disrupt your sleep and diminish your appe- tite. Instead of feeling energetic and mentally focused, you lose energy, and your judgment becomes impaired. Parts of your brain stop communicating with each other, and brain tissue shrinks in the regions that control learning, memory, and rational thought.
Your brain has no way of knowing whether you’re watching Mad Max: Fury Road or viewing real-life events. Your prefrontal cortex tells you that you’re watching sequences of still images projected at a rate of 24 frames per second. Meanwhile, your amygdala gets your heart pounding as the War Boys chase Max Rockatansky across a post- apocalyptic Australian landscape.
If your brain can’t tell the difference between what’s dangerous and what isn’t, then everything is a potential threat, and you’re in for a lot of false alarms. For example, your prefrontal cortex is responsible for remembering that your ex-wife is a petite brunette who dumped you. Your amygdala is in charge of flooding your body with rage whenever you see a woman who even vaguely resembles her. And vaguely is the operative word here, since the amygdala, in its effort to determine whether that petite brunette in the coffee shop presents a clear and present danger, rapidly evaluates her against your store of emotionally charged memories. The amygdala’s motto is “Better safe than sorry,” and so if it finds any key similarity at all—a tone of voice, a facial expression—it instantly activates its warning siren and sets off an emotional explosion in your body. So if you’ve ever wondered why anger has a way of stirring up memories of long-ago threats and painful events, now you know.