Kurland also brings up the fight-or-flight response. Your body gets ready to either throw hands or retreat. It's a reaction that's a part of your autonomic nervous system, a.k.a, it's an involuntary response. "The amygdala in our limbic system of the brain sounds an alarm," Kurland says, the end result being the release of adrenaline into our blood. "When we see a text from our ex, depending on how we perceive this text and what it emotionally triggers for us, it might send us into a fight-or-flight response."
The other response your body would have at your ex's name popping up on your lock-screen is to release cortisol, "the stress hormone. It plays a part in a phenomenon similar to fight or flight called the "challenge" vs. "threat" response.
"When we encounter a stressor — like a text from an ex —there are two primary ways we can react. We can either one, believe we have the resources cope with the demands of the task. Or two, we can feel like the demands of the task outweigh our coping resources," Smith says. Essentially: Are you going to face whatever your ex said head-on, remaining #unbothered? Or are you going to get overwhelmed with crafting the perfect response and panic?
When challenge mode kicks in, cortisol jumps, and so does the body's levels of dehydroepiandrosterone (DHEA). "Our body prepares itself for action," Smith explains. "Our veins open up and our circulation improves, so that our extremities (including the brain) have the blood they need to get the job done — in this case, carefully thinking through what we might want to say to our ex and typing the response out confidently."
Cortisol rises in threat mode, but DHEA levels stay low. Basically, you feel shook. "Our veins close up and our circulation slows down, so our brains and other extremities are weakened, and a bit starved for blood and oxygen," Smith says. "This means we might struggle thinking clearly. And when we try to type the response, our fingers might even feel numb and shaky."
Kurland adds that cortisol shuts down our higher cortex's ability to step back and see the bigger picture. "We are overcome by a kind of tunnel vision, and we would be more inclined to react impulsively and defensively," Kurland says, like hitting "send" on a text we'll probably regret.