In the 2001 trial of the United States Court of Appeals for the Ninth Circuit’s case of Landrigan vs. Stewart was a great example of how behavioral genetics can have both a negative and positive effects on criminal cases Landrigan had filed a petition because he claimed he did not have an effective counsel during the penalty phase of his capital case (Farahany, Beret).. After four years of being sentenced he said he would have been cooperative if his attorney tried to offer evidence, that his biological background ‘made’ him a criminal. Even with his effort to chance his sentence the Ninth Circuit was unmoved. His background showed the court room his genetics will make him still violent in the future, because he cannot change his genetic…show more content… It was not a topic that was brought up earlier, because there was tainted history of using biology to figure logistics of criminal behavior. Instead, criminologists look at social and environmental factors such as poverty rates, drug/weapon accessibility, and socialization. Over 100 studies have shown genes play a role in crime. Kevin Beaver, an associate professor at Florida State University’s College of Criminology and Criminal Justice states approximately 50 percent of a human’s aggressive behavior is comprised of the thousands of expressed genes affected by the environment (Cohen). The other half of a human’s aggressive behavior is usually environmental or social factors such as, neighborhood, wealth, and education. It is important to also know the other factors that “make” someone a criminal because it will also help researcher see what else contributes to criminal activity (Eysenck).
Originally, researchers and scientists thought a duplication in the Y chromosome was the connection between how genetics influence crime. The male karyotype would be XYY instead of XY. They have a tendency for hyper-aggressiveness and violence (Wachbroit). This unique karyotype also leads to a significant number of abortions if the fetus carries the karyotype. The other effects of this mutation are men that are taller, less intelligent, hyperactive, and are more impulsive (Wachbroit). After much research no one could relate this to how it