The Field Guide › Article
The foundational definition, building on Edmondson's 1999 formulation: psychological safety is an emergent property of a group, not a personality trait, a vibe, or a management technique. When a group has it, people can reasonably predict that others will react positively when they speak up, ask for help, admit a mistake, or challenge an idea — and that positive predictability is what makes the risk feel worth taking. Ambiguity about norms, expectations or purpose is one of the most reliable ways to silence people. Traces the convergent history (Rogers in the 1950s, Schein and Bennis in the 1960s, Kahn in 1990, alongside aviation human factors, Deming's 'drive out fear', and Toyota's Andon Cord) to argue there is far more evidence about what works than a casual reading suggests. Clarifies what PS is not: not comfort, not niceness, not the absence of accountability, and not something leaders simply bestow from above (the leader-centric framing is a subtle version of the problem it claims to solve). Sets out the two-gate model of silence — ambiguity failure (people can't read whether raising something is appropriate) and valence failure (people see the problem clearly but the personal cost feels too high) — and shows how steep power gradients drive the second. Covers the benefits (faster learning, fewer and better-caught errors, retention), the least-safe-person principle, the relationship with accountability and just culture, Clark's four-stage model, Westrum's typologies, the work-as-imagined vs work-as-done gap, and the cautions around measurement.