The principle
Humans are creatures of habit, desperate to read each other. Take that comfort away and they exhaust themselves trying to anticipate you.
The application
Vary one or two things people use to predict you — your decision time, your meeting cadence, what you praise — and you become harder to manipulate. The trick is to remain reliable on the things that matter (delivery, integrity) while becoming unreadable on the things that do not.
The defensive tell — how to spot it being run on you
When a boss or peer suddenly changes their pattern (faster decisions one week, total silence the next), do not over-interpret. The unpredictability may be deliberate. Anchor on what is being delivered, not on what is being signalled.