The idea of the Inner Lizard is inspired by a theory called the Triune Brain Model. It argues that our brains have three separate sections: the limbic, the neo-cortex, and the reptilian brain. The latter is the primal part of our brain that focuses on survival. At Juniver, we call this the Inner Lizard.
This model is out-of-date now that we know that the brain is not compartmentalized into sections. Instead, research shows that the brain functions as one unit. Still, the idea of a lizard-y part of our brain is helpful when it comes to understanding impulses at play in disordered eating.