When a leader allows defensive behavior to persist unchallenged in a team, communication gums up. Other team members become scared to say things to the defensive person, and eventually stop sharing openly with anyone. The entire team’s communication degrades because of one tolerated pattern.
The nuance is in how you address it. Saying “we don’t allow defensiveness here” is itself defensive. A better approach is to name what you see with care: “I see that you’re being defensive — this isn’t something we do here. Take a break, get back to yourself, come back and we’ll continue.” Or even better: help them name the underlying feeling. “Am I being told I’ve done something wrong? What’s happening?” — turning the defensive reaction into a vulnerable expression of fear.
The key insight is that defensiveness is a nervous system response to perceived threat. The goal isn’t to forbid fear but to create a culture where people can say “I am afraid right now” instead of armoring up.