The "fight-or-flight response" is one of those ideas self-help authors have wrenched with gusto out of its scientific context, with predictably messy results. The worst example of this happened to quantum physics (visit quantumjumping.com for exciting tips on how to use the theory of multiple universes "to pick up new skills… like painting [or] photography"). By contrast, and however much it's been distorted, fight-or-flight remains a useful way of seeing our tendency to react like startled animals when faced by stress. Speaking broadly, the prefrontal cortex – the reflective part of the brain – shuts down and the amygdala, the lizard brain, which is responsible for our animal instincts, takes over. Steeled for combat or readying for escape, we switch into "survival mode" – useful for running away from predators, but a misery-inducing approach to the manifold minor stresses of modern life.

There's an element of fight-or-flight involved, arguably, not only in angry encounters, but whenever we find ourselves doing things we "know" we shouldn't. Impulse buying, procrastination and compulsive eating can all be seen as ways to escape some feeling we'd rather not experience. The problem with self-help's usual antidotes, though, is precisely that survival mode is unreflective: in its grip, you can't possibly recall that 15-step plan for building better habits, or that clever technique from that book on neurolinguistic programming. Which is why I love the aggressive simplicity of what Tony Schwartz, writing on the Harvard Business Review's website, calls The Golden Rule of Triggers: "Whatever you feel compelled to do, don't." Instead, he says, take a deep breath, and "feel your feet" – a distraction to pull yourself out of your head.

We've all had occasion to tell ourselves or others to "take a deep breath" or to "count to 10" before exploding in rage. What Schwartz's rule removes, though, is the need to reflect on whether or not we're in such a situation. Instead, it recommends learning to interpret any sign of compulsive behaviour as an indication that the action is probably unwise. Rather than battling compulsion, it co-opts it as a warning system.

There's still a small element of contradiction here: in the unthinking heat of survival mode, you can't stand back enough even just to see that you're acting compulsively. But the complete takeover of your brain by fight-or-flight usually lasts only a split second – enough time for the finger to reach for the mouse button, say, but not quite long enough to press it and send that ill-considered angry email. The crucial moment is the next split second, as reflective thinking kicks back in and you dimly perceive that you're acting compulsively. The Golden Rule of Triggers may be stupidly, laughably simple. But in that tiny gap between the total grip of survival mode and doing something you'll regret, simple rules are all you'll be capable of following.

In its pleasing sense of oppositeness, Schwartz's rule recalls the anti-procrastination Rule of Resistance, which states that whatever task you least feel like getting down to is probably the one you need to be focusing on. Neither rule is necessarily "true" in some ultimate sense. But both serve to harness our lizard brain's faults in service of our higher-order goals – enabling what I probably ought to refrain from calling a quantum leap towards achieving the things that really matter.

oliver.burkeman@guardian.co.uk; twitter.com/oliverburkeman