It’s the “brain stem” at the top of the spine.
It is automatic and compelling - more so the greater the danger.
Causes adrenaline to course through the body, unless overridden by offsetting thoughts or the higher brain.
Left by itself, reptiles are more combative and tend not to nurture.
1) Hippocampus – Memories/experiences emblazoned in brain, stronger based on level of emotion
2) Amygdala – Able to “feel” emotions and to create “emotional memories.”
See, below, how these affect us.
Function is to balance the other brains. It allows us to problem solve, analyze, judge, control impulses, and organize information, to learn from past experience and to empathize with others.