Then that person reacts to us, and our emotional response to their reaction also changes brain chemistry a little bit. So after every interaction, we update our neuro-chemical profile of the world and of that relationship. The amazing thing about the human brain is that it is so flexible, and it is very adaptable. We are born with some things. We don't come with a blank slate.
Some babies are very excitable, some are very laid back.
And those differences in activity level, reactivity, and sensitivity are the basics of temperament. It's what we bring to the situation. Then the way those characteristics fit with our particular environment goes on to shape that temperament and our behavior. The most important programming goes on in the circuitry that governs emotion and response to the challenges of life, the stress. Our ability to shape those neuro-systems to fit our own particular environment helps us to adapt to a particular situation.