Specific neurons and neurotransmitters such as norepinephrine, trigger a defensive state when we feel that our thoughts have to be protected from the influence of others.

If we are then confronted with differences in opinion, the chemicals that are released in the brain are the same ones that try to ensure our survival in dangerous situations.

In this defensive state, the more primitive part of the brain interferes with rational thinking and the limbic system can knock out most of our working memory, phisically causing “narrow-mindedness”.

We see this in the politics of fear, in the strategy of poker players or simply when someone is stubborn in a discussion.

No matter how valuable an idea is, the brain has trouble processing it when it is in such a state.

On a neural level it reacts as if we`re being threatened, even if this threat comes from harmless opinions or facts that we may otherwise find helpful and could rationally agree with.

But when we express ourselves and our views are appreciated, these “defense chemicals” decrease in the brain and dopamine neurotransmissiion activates the reward neurons, making us feel empowered and increasing our self-esteem. Our beliefs have a profound impact on our body chemistry, this is why placebos can be so effective.

Self-esteem or self-belief is closely linked to the neurotransmitter serotonin. When the lack of it takes on severe proportions, it often leads to depression, self-destructive behavior or even suicide.

Social validation increases the levels of dopamine and serotonin in the brain and allows us to let go of emotional fixations and become self-aware more easily.

This quote comes from Athene’s Theory of Everything