This is what sociopathy looks like. This is what some of us mean when we talk about "lizard people."

Sociopaths operate emotionally from the more ancient, reptilian part of the brain.

We all have that reptilian part, but normal humans operate emotionally from the higher, mammalian part of the brain.

This is why sociopaths have little to no empathy for other living creatures, but normal humans do.

"Lizard people" is a reference to having the emotional range of a reptile. They are not lizards in the physical sense, but in the emotional sense.

That is what makes them so extremely destructive to everyone around them, whether they're your parent, spouse, boss, or leader.

You cannot change this no matter what you do, because emotionally they are reptiles - not mammals.

Source: The Dragons of Eden by Carl Sagan. There are many other sources for this, too.