Introduction: We in the 1990s are slowly and inevitably being faced with the sociological and biological implications of impending genetic power.
This power is analytical, particularly in cases such as the Human Genome Project, which aims to map out the genetic code for the entire human genetic composition. Additionally, this power is preventative and participatory, as it can be and is being used to control the behavior of humans and other animals. However, many view this new power as risky and potentially hazardous, similar to atomic energy. It must be treated with care, used under close supervision, and performed with professional consent and observation. Otherwise, people will begin to see this new genetic power as a dangerous drawback rather than an advancement of human culture.
One of the most highly contested and objectionable topics of genetic power is the analysis of crime, violence, and impulsivity. While most agree that children are not born with a natural affinity for violence and crime, new genetic studies are beginning to search for the hereditary basis for impulsivity. As these studies continue, child testing programs, drug manufacturers, civil rights activists, lawyers, and anxious citizens await the resulting testimony of the scientists.
The social implications of the genetic search for aggressive tendency are seen by some as a great step forward, by others as a dangerous power with the ability to give birth to another Holocaust, and by still others as racist. At one time, it was believed that one’s character could be determined from the bumps on one’s skull. Much later, in the 1960s, as science marched on in its regular pace, it was theorized that carriers of an extra Y chromosome were predisposed to criminality. Today, we are faced with the power to determine and alter one’s character through genetics. We must collectively decide whether the ultimate price, not of money but of natural evolution, is worth the ultimate result.
Behavioral Genetics and Aggression.
One day in 1978, a woman entered the University Hospital of Nijmegen, the Netherlands, with complaints regarding the men in her family. Many of the men seemed to have some sort of mental debility, including her brothers and her son. In time, a pattern of strange behavior of the men emerged. One had raped his sister and, upon being institutionalized, stabbed a warden in the chest with a pitchfork. Another tried to run over his boss in an automobile after he had criticized the man’s work. A third had a regular habit of making his sisters undress at knife point, and two more were convicted arsonists. Additionally, the known IQs of the men were typically around 85. The history of this sort of behavior was found to be typical, as nine other males in the family, tracing back to 1870, had the same type of disorder. It became evident that there was something wrong in the lineage of the family.
Hans Brunner, a geneticist at the University Hospital, has been studying the family since 1988. It was discovered that the men had a defect on the X chromosome that helps regulate aggressive behavior. Brunner was cued to the fact that the defect was on the X chromosome because the trait was passed on from mother to son, and none of the women were afflicted. The gene normally codes for the production of the enzyme monoamine oxidase A (MAOA), which breaks down three important neurotransmitters that trigger or inhibit the transmission of nerve impulses. One of these neurotransmitters is norepinephrine, which raises blood pressure and increases alertness as part of the body’s fight or flight” mechanism. Brunner believes that the lack of this neurotransmitter could cause an excess of chemical messages to the brain, in times of stress, causing the victim’s fury.
The men’s urine showed extremely low levels of the breakdown products of three neurotransmitters, which are the products after MAOA has done its work. One of these chemicals is serotonin, which inhibits the effects of spontaneous neuronal firing and exerts a calming effect. The lack of this inhibitor is held responsible for the Jekyll and Hyde” personalities of the afflicted men and may be responsible for their low IQs. Over the course of four years, Brunner was the first to link and pinpoint a single gene to aggression. He also analyzed the X chromosomes of 28 members of the family, compiling sufficient evidence to prove his discovery. However, Brunner never studied the influence of a shared factor.
