share any of these common genetic underpinnings. Several experiments use individuals with antisocial parents who have been adopted and raised by other people. Consistently, however, antisocial behavior prevails in the child despite the deviant, biological parents being absent. One such experiment used individuals whose biological parents exhibited criminal behavior and who were adopted. When the adoptive environment was adverse and the genetic predisposition was present, 40% of the adoptees partook in criminal activity compared to only 12.1% with only genetic predispositions. In another study, significant heritability was found for crime, but one subsequent finding was that heritability was higher in individuals from high socioeconomic background and those from rural areas. This shows the link between antisocial behavior and biological risk will be stronger in individuals from kindly social backgrounds than individuals from adverse social backgrounds "because the social causes of crime camouflage the biological contribution. While several studies have been initiated to identify the alleles responsible for antisocial behavior, no such discovery has been made thus far. Minor Physical Anomalies and Environmental Interactions In one study testing 129 boys from age 12 to 21 years with minor physical anomalies (MPAs), the correlation between antisocial behavior and MPAs only existed when the individual suffering from an MPA was exposed to an adverse home environment. This environment was necessary to express the biological predisposition just like an environment is necessary to express certain genes. Brain Activity and Environmental Interactions A link between prefrontal cortex dysfunction and antisocial behavior has been found in many studies. Some frontal lobe lesions have been responsible for impulsivity and disinhibition, which are key characteristics of Antisocial Personality Disorder. In one such study, a group of murderers were divided into two groups: one with benign social backgrounds and one with malignant social backgrounds. Using positron emission tomography (PET) scans were used to detect function in different parts of the brain. Compared to a normal control group, the murderers raised in malignant environments had relatively good prefrontal functioning, but the murderers raised in benign environments had significantly reduced prefrontal functioning, mainly in the right hemisphere. Functional MRI scans were used in another study with violent offenders and abusive environments. Four groups were composed of non-violent controls with no history of abuse, violent offenders with a history of abuse, violent offenders with no history of abuse, and non-violent controls with a history of abuse. The violent offenders who had been