The term ‘Primal brain’ (also called the lizard or reptilian brain) refers to the oldest parts of our brains which are responsible for basic functions like breathing, eating and sleeping. The primal brain is also responsible for our emotions and instincts that we do not consciously control.
To make conscious decisions we need our ‘rational brain’; the part of the brain that in everyday situations makes us behave like civilized human beings. If it weren’t for the rational brain, we would still be acting like primates.
Still, the primal brain is cunning and occasionally convinces the rational brain into sweet talking our ‘gut decisions’. It subconsciously makes the rational brain come up with reasons why the emotional decision is the best and only decision.