What Makes Serial Killers Tick?

"After I'm dead, they're going to open up my head and find that just like we've been saying a part of my brain is black and dry and dead," said Bobby Joe Long, who suffered a severe head injury after a motorcycle accident. According to many researchers, brain defects and injuries have been an important link to violent behavior. When the hypothalamus, the temporal lobe, and/or the limbic brain show damage, it may account for uncontrollable aggression.

The hypothalamus regulates the hormonal system and emotions. The "higher" brain has limited control over the hypothalamus. Because of the physical closeness of sexual and aggressive centers within the hypothalamus, sexual instinct and violence become connected for lust murderers. The hypothalamus may be damaged through malnutrition or injury.

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.

The temporal lobe is highly susceptible to injury, located where the skull bone is thinnest. Blunt injuries, including falling on a hard surface, can easily damage this section of the brain, creating lesions, which cause forms of amnesia and epileptic seizures. Damage to the temporal lobe can result in hair-trigger violent reactions and increased aggressive responses. As a child, Ken Bianchi fell off of a jungle gym, and landed on the back of his head. He soon began to have epileptic seizures.

Researcher Dominique LaPierre believes that the "prefrontal cortex, an area of the brain involved in long-term planning and judgment, does not function properly in psychopathic subjects." 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.

Some of these brain injuries are accidental, but many of them were inflicted during childhood beatings. Among the many serial killers who had suffered head injuries are Leonard Lake, David Berkowitz, Kenneth Bianchi, John Gacy, and Carl Panzram, who, as a child, had some sort of head infection. "Finaly my head swelled up as big as a balloon. ... I was operated on in our own home. On the kitchen table," he wrote. "I would sure like to know if this is the cause of my queer actions." Ted Bundy, however, had extensive X-rays and brain scans, which revealed no evidence of brain disease or trauma.

No Fear

Crime Times reports on findings that psychopaths have a greater fear threshold, and are less likely to respond to fear-inducing stimuli, such as sudden, loud noises. In other words, psychopaths may be immune to fear. The psychopath's heart rate and skin temperature are low, and their "startle reaction" was substantially less than the average person. The autonomic nervous system of intensely violent people is intensely sluggish. ... They need a higher level of thrill or stimulation in order to have an intense experience," says forensic psychologist Shawn Johnston.

Sensory deprivation

Studies show that the lack of physical touch can be harmful to the child's development. In a study of chimpanzees, the babies who were not handled became withdrawn, and later began to attack others. Some serial killers had been separated from parents at early age, or were denied their mother's love and physical touch.

Conclusion

These physiological characteristics, however, do not guarantee a serial killer. Many, who are not violent, have brain injuries and biological abnormalities. 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. Many of these biological studies are new, so perhaps in the future the chemical profile of serial killers will be revealed.