Interesting Fact:

Many serial killers have experienced some sort of brain trauma, one of the areas is called the limbic brain. The limbic brain is the part of the brain associated with emotion and motivation. When the limbic brain is damaged, the individual loses control over primary emotions such as fear and rage. The predatory gaze of the psychopath, according to Meloy, lacks emotions, and is as cold as a reptile's blank stare. Reptiles are missing the limbic part of their brain, where memories, emotions, socializing, and parental instincts reside. In other words, serial killers are aptly described as "cold-blooded," just like their scaly reptilian brethren.