Highly defensive people are very sensitive to certain subjects causing them to go into a sort of fight or flight response. After all, why jump into a defensive posture unless you think there’s a threat? 

The threat is typically not realistic, but that’s only an outsider’s perspective because to the person with the defensive behavior, the threat could be very real to them. But what exactly are they threatened by?

I received a letter from a listener that was dealing with a defensive person at work. Her coworker would get very defensive whenever anyone would talk about “controversial subjects” around her. The letter writer didn’t tell me exactly which controversial subjects were being discussed, but I could only assume that they were the typical ones that most people have a very staunch opinion on.