The lizard brain

The term "lizard brain" is coined by Seth Godin, in his new book ' The icarus deception'.
I read an article on the book, and "lizard brain" is:

Whether you know it or not, we all have what Godin refers to as a lizard brain. He says, "The lizard is a physical part of your brain, the pre-historic lump called the amygdala near the brain stem that is responsible for fear and rage and reproductive drive."

Godin has written a lot about this in previous books including Linchpin and Poke the Box and cites author Steven Pressfield for further explanation -- “As Pressfield describes it, the lizard brain is the resistance. The resistance is the voice in the back of our head telling us to back off, be careful, go slow, compromise. The resistance is writer's block and putting jitters and every project that ever shipped late because people couldn't stay on the same page long enough to get something out the door. The resistance grows in strength as we get closer to shipping, as we get closer to an insight, as we get closer to the truth of what we really want. That's because the lizard hates change and achievement and risk," Godin says in The Icarus Deception.

Quieting the lizard brain is a constant struggle for entrepreneurs. It is a skill that needs to be developed. But as we tune into the frequency of what we feel is the right decision and tune out the lizard brain we will be able to truly test our business plans and hypothesis.

The full article: Here