Its what we commonly call the fight or flight system. Another automatic system, mainly in charge of protecting us from threats by driving immediate emotions and actions.
Why is it valuable to understand the brain's automatic patterns?
Defensive responses, even mild negative stress, can severely reduce deep thinking (it literally reduces the activity of the pre-frontal cortex). It bypasses our most clever deliberate thinking.
The fight or flight system has a tendency to respond to personal affronts (and other everyday indignities) with the same strength as actual physical threats. While the threats we actually face require the thoughtful approach rather than the survival footrace. With time and repetitions, it sets us up for chronic stress and robs us from thinking expansively (especially when it is most needed).
In dangerous situations, let’s imagine you hold a burning cup, the defensive response bypasses form of slow and complex analytical processing and you let go of the cup even before feeling the burn.
The same logic is applied to social context, if someone suggests you are at fault, chances are you'll start defending yourself. Even if you don't express it, your brain will gather all the evidence it has stored proving you are not guilty (whether you are indeed at fault or not). Like for the tea cup, defence kicks in whether you like it or not.
While the defence system is on the look for threats (physical or social) the discover system, sits at the opposite, on the look for potential treats. Its expansive and relaxed. It also looks for survival cues but the intention is subtler and takes interest in elements of praise, novelty or pleasure.
Is it dangerous to live constantly in the defence mode?
Triggered too much and too often, and effectively living in defence mode, can results in severe stress... And associated disorders.
Is it possible to trigger the discover mode?
Technically, yes. At least up to a certain extent.
Noticing is the 1st step to disarming the defence mode.
In the context of communication tapping into the discover mode ensures deeper attention and engagement, while signalling danger and triggering the defence mode might cause aversion, fear, shut down, avoidance, or even denial.