Removing the Folklore

Almost every personal-safety course in the country teaches a color code of readiness states. It came from Jeff Cooper's firearms instruction in the 1970s, adapted from a military alert scheme. Cooper offered it as a statement about willingness to act rather than a model of attention.

No controlled research validates its stages or shows that self-classifying into them improves any outcome. Even writers inside that training culture note it is routinely misapplied as an attention monitor it was never built to be. Keep it as vocabulary if it helps; do not mistake it for science.

What has a research base is Mica Endsley's three-level model, published in Human Factors in 1995 and validated across aviation and other high-workload domains. Level one is perception — what is present. Level two is comprehension — what those elements mean together. Level three is projection — what happens next if nothing changes. It is the level that buys time, because it produces the decision to change route before anything has happened.

Then the instruction that does active harm. “Stay alert at all times” fails twice. Sustained vigilance degrades measurably within tens of minutes; that is one of the oldest findings in human factors.

And persistent threat scanning has a clinical name: hypervigilance is a diagnostic feature of PTSD, studied as exhausting and self-perpetuating. Eye-tracking work with trauma survivors found it drove more and wider scanning of neutral but ambiguous scenes. Training that produces a permanently scanning person has trained a symptom.

There is also a hard ceiling on what attention can do. In Daniel Simons and Christopher Chabris's 1999 study, about half of observers concentrating on a counting task failed to notice a person in a gorilla suit walk through the scene. In a 2013 study by Trafton Drew, Melissa Võ and Jeremy Wolfe, radiologists missed a gorilla image inserted into a lung scan. Expertise does not fix it.

So: cued scanning. Deliberate, brief environmental updates at transitions — leaving a building, approaching a vehicle, entering an unfamiliar space — with genuine rest in between, and the phone away at those specific moments rather than all of them. Design around the limit instead of exhorting past it.