Defensiveness can take on many forms. These are often called defense mechanisms in the psychology world. It is important to remember that everyone has defense mechanisms and that they are a normal and primitive part of social development. They are most obviously seen in small children. If a toddler wants to avoid bath time, they run away. This doesn’t mean they will successfully avoid bath time but they are avoiding the conflict or perceived “threat”. Yes, bath time is the perceived threat, even though it logically is not a threat, the mind of a 2-year-old views it as something they don’t want to do. This is an important point because it can be difficult to understand sometimes what the “perceived threat” is and sometimes can be hard to pick up on the defense mechanism.
As we get older, we get better at defense mechanisms. Instead of running out of a stressful meeting, perhaps we simply shut down and don’t contribute. A good sign of someone feeling defensive is if there is some form of passing blame and/or taking a victim role. Common defensive mechanisms are denial, avoidance, acting out, compartmentalization, and even regression.