We find ourselves asking, "What turns a person into a serial killer?" According to paleopsychology our civilized brains are built on a primitive animalistic core known as the R-Complex. Paleopsychologists also believe that there is some sort of malfunction in the brain of serial killers, that somehow their primitive brain overrides the "higher" brain: reason and compassion take a backseat to lust, aggression, and appetite. A study by Pavlos Hatzitaskos and colleagues reports that a large portion of death-row inmates have had severe head injuries, and that approximately 70% of brain-injured patients develop aggressive tendencies. .
While we still may contain the savage instincts from our ancestors, the vast majority of individuals have the intelligence, reasoning, and logic to keep this brute nature in check. Theorists of Freud see this explanation quite similarly, except that they speak of the id. They believe that serial killers are not necessarily ape-men but have profoundly stunted personalities, stuck or fixated at an infantile stage of psychosexual development. Because of trauma during childhood, compulsive killers, never develop or progress their emotional development past that of a two-year old. Like a two-year old, the killer likes to destroy things and views a person as another breakable object to be taken apart for pleasure. Other explanations include physiological and sociological influence; but what the real nature of these individuals is often leaves us wondering because the true root cause may never be known. These physiological characteristics, however, do not guarantee a serial killer. Many have brain injuries and biological abnormalities that are not violent. A lump on the head is no singular forecast for a serial killer. Can evil be reduced to a chemical equation? Perhaps it is a combination of environment and chemical predispositions. What we do know is that no singular pattern emerges for serial killers.