Despite endless research conducted in this area of ​​study, researchers still struggle to determine the cause of serial killers. So the main question is: are serial killers born or made? As previously noted, researchers have identified a series of biological predispositions linked to these groups of people. In fact, since the dawn of time, it has been believed that criminals are born, not made. Dating back to the 19th century, Lombroso examined the phenotypes of Italian criminals to determine whether criminal characteristics could be passed down from generation to generation. He theorized that criminals were born callous and cruel while lacking remorse. Lombroso also mentioned that these individuals tended to be antisocial. Although many of these theories have been disproven by modern research, researchers have admitted some underlying truths from outdated studies. Take for example Lombroso's experiment, which was able to distinguish a hereditary link between future violent behavior. Interestingly, genetics accounts for approximately 40-60% of antisocial and aggressive behavior. According to adoption studies, there is a 12.1% chance that a child will develop violent tendencies if their biological parent is abusive. Jeffrey Landrigan is a perfect example. Landrigan was put up for adoption when he was born. Growing up, he exhibited several delinquent behaviors. At the age of 20, Landrigan murdered his first victim. By the age of 25, Landrigan had killed two people and was sentenced to death. In prison, it was discovered that Landrigan was related to another inmate, Darrel Hill, who was his father. Like his father, Landrigan had abused drugs and twice committed murder. It was also discovered that Landrigan came from a criminal family where his grandfather and great-grandfather were also criminals. Landrigan's story and many others like his are important in developing a better understanding of crime and serial killers in general by examining correlations between genetics and violent behavior. To reference the statistics above, genetics can play a significant role in an individual's future, particularly in their likelihood of becoming a delinquent. This is crucial information for a variety of reasons. Not only does this provide insight into why an individual may engage in brutal crimes, but, more importantly, research suggests that regardless of race, gender, or social class, genetics has a universal effect on fate of human beings. Say no to plagiarism. Get a tailor-made essay on “Why Violent Video Games Should Not Be Banned”? Get an original essay Despite their family history of crime, serial killers often suffer from a range of disorders. Of 57 adolescents accused of homicide, 64% had developmental problems related to disruptive behaviors, such as conduct disorders, attention deficit hyperactivity disorder (ADHD), and autism spectrum disorders. Recent studies have found that violent offenders are often diagnosed with a neuropsychiatric disorder during childhood and are often associated with their criminality. Individuals diagnosed with conduct disorder showed decreased prosocial behavior and physiological responses in stressful situations as well as increased psychopathic tendencies. These individuals were less likely to help and feel sympathy toward others, leading them to react poorly during eventsemotionally stimulating. Due to these individuals' lack of awareness of others' emotions, their interpersonal relationships were negatively affected. As a result, it is common for these individuals to engage in antisocial behaviors linked to adult criminality. Despite the small population, similar results were obtained among offenders diagnosed with ASD. These people have been said to have difficulty understanding and processing nonverbal communications. It is for this reason that offenders are unable to develop strong relationships with their peers, leading them to find themselves socially isolated and unable to fully understand the effects of their actions on others. It is therefore not abnormal that these individuals engage in more brutal crimes. According to Loana (2013), individuals with Klinefeleter syndrome (KS) are five times more likely to become a serial killer than the general public. KS is a chromosomal mutation that results in the location of an extra sex chromosome (X) in men. A similar disease has been discovered, in which an extra Y chromosome appears in the biological makeup of the individual. This is called the “crime chromosome,” because its frequency among criminals is 10 times that of the general population. A national study confirms this ideology after studying the criminal patterns of men aged 15 to 70 diagnosed with KS and XYY. It was found that men with an extra sex chromosome were more likely to be convicted than the general public. A significant increase was seen in perpetrators of sexual abuse, burglary, arson and “other” convictions. These high conviction rates are believed to be due to low IQ levels and poor socio-economic status. It is common for men diagnosed with these illnesses to suffer additional psychiatric disorders, psychophysiological dysfunctions, and/or increased sexual deviation. These sexual deviations would be due to the confusion attached to the sexuality of these individuals and the inability to distinguish socially and legally accepted behaviors; which explains the high levels of convictions for sexual abuse among these people. Brain Regions and Chemical Imbalances The brain is a complex, organized structure that controls how humans think and behave. It is separated into two parts: the left and right hemispheres; functioning bilaterally. A crossover of information occurs and is dominated by the left or right hemisphere. This results in the left side of the body being controlled by the right hemisphere and vice versa. It is important to note that the brain is location dependent; which means that each region has its own specific function(s). Thus, damage to a region can lead to specific behavioral outcomes. These findings are usually noted as dysfunctions, because the individual is unable to produce the same behaviors as a generally healthy person in the same environment and situations. In recent studies, a strong positive correlation between serial killers and head trauma has been discovered, where an increase in violent behavior is thought to manifest after trauma. This can occur either during childbirth or following an unfortunate event, such as a fall or blow to the head. Take Robert Long for example, after he got into a motorcycle accident and suffered a head injury. There has been an increase in violent behavior, which has led to the commission of violent crimes. Long was said to have suffered injuries..