The amygdala is a small part of the brain often linked to the processing of emotions, especially fear. It tells the body to release chemicals such as cortisol when a fear response is triggered, and it often processes data more quickly than other parts of the brain, such as the neocortex.

Gonzales discusses the amygdala often because managing your fear response is a large part of success in a survival situation. While he acknowledges that the fear response is an ancient protective instinct, he says it hasn’t caught up to modern problems, which often require more complex solutions.

Rock climbers belay by fixing a rope to an anchor or another person and attaching it to their harness as a safety back-up in case they fall. Climbers can belay up or down a mountain surface. Gonzales mentions belaying in many of his mountaineering stories. He emphasizes that belaying from a fixed anchor is always the safest option, since sometimes climbers attach themselves by rope to each other to belay, which can cause a fatal domino effect if one climber falls and pulls the others down with them.