Imagine you are a gazelle on the African savanna. A lion appears. Your sympathetic nervous system fires instantly: adrenaline floods your muscles, your heart rate spikes, blood diverts from your digestive system to your legs. You run. You either escape or you do not. Either way, the event is over in minutes.
Now imagine you are a human at a desk. Your inbox shows 47 unread messages. Your manager has scheduled an "unexpected meeting" for 3pm. A Slack notification pings. Your phone buzzes.
Your nervous system responds with the exact same cascade. Adrenaline. Cortisol. Heart rate increase. Blood diverted from digestion. Muscles tensed for flight.
But you cannot run. You cannot fight. There is no resolution event — just a slow, persistent drip of threat signals from a world your nervous system was never designed to interpret.
The Evolutionary Mismatch
This is what researchers call evolutionary mismatch. Your stress response evolved for acute, short-duration threats with clear resolution. Modern stressors are chronic, ambiguous, and never fully resolve. The lion leaves. The inbox does not.
The physiological cost is enormous. Chronic sympathetic activation — living in a permanent low-grade fight-or-flight state — suppresses immune function, disrupts sleep, impairs digestion, and fundamentally alters brain architecture over time. The hippocampus (memory and learning) actually shrinks under sustained cortisol exposure.
Completing the Stress Cycle
The solution is not to eliminate stress. It is to teach your nervous system to complete the stress cycle — to move through the activation rather than getting stuck in it.
Your body already knows how to do this. After a gazelle escapes a lion, it literally shakes — a full-body tremor that discharges the stress hormones and returns the nervous system to baseline. Humans have the same capacity, but we have socialized it out of ourselves. We brace instead of release. We hold instead of shake.
The 60-Second Discharge
One accessible practice: after a stressful event (or at the end of a workday), stand up and deliberately shake your hands, arms, and shoulders for 60 seconds. It will feel silly. Do it anyway. Then take three slow breaths and notice what happens in your body. This simple discharge pattern helps your nervous system complete the cycle it was trying to finish.
The Nervous System That Evolved for Savannas, Not Spreadsheets guides you through a deeper version of this recalibration.