Most companies have a security policy somewhere. Fewer companies have a security culture, and the difference shows up exactly when it matters most.
A policy tells people what the rules are. A culture is what people actually do when nobody is checking. It shows up in whether someone reports a suspicious email or just deletes it, whether a developer flags a security concern in a code review or lets it slide to hit a deadline.
Building that culture starts with leadership treating security as part of doing good work, not as a separate compliance task handled by one team. When engineering, product, and leadership all treat security as a shared responsibility, it stops feeling like a burden imposed from outside.
It also means making the secure path the easy path. If following good security practice takes ten extra steps, people will find a way around it, not because they do not care, but because deadlines are real. Good tooling and clear, simple guidance remove that friction.
Psychological safety matters more than most companies realize. If reporting a mistake, like clicking a phishing link, leads to blame, people stop reporting. If it leads to a quick, blame-free response, the business finds out immediately instead of weeks later.
None of this replaces technical controls, audits, or testing. But a business where people genuinely care about security tends to catch problems faster and recover from them better than one that only has a document saying they should.