Researchers in Berlin have managed to isolate 50 causes for intellectual disability at the genetic level, some of which may be responsible for such mental disorders as autism and schizophrenia. By studying specific recessive defects which have occurred in families in which the defects are more prevalent, they were able to further isolate the specific genes which cause the defect.
In Helinski, psychiatric researchers have been looking into the genetic roots of psychopathy, among other mental tendencies. Through careful study of over 100 psychopathic prisoners for seven years after their release, the scientists were able to determine a correlation between a gene called monaamine oxidase and a repeat offense of violent crime. To be specific, those with “high activity” monoamine oxidase were reported to be almost seven percent more likely to commit another offense after release.
Even your political leanings have been correlated to a single specific gene. A dopamine receptor gene, DRD4, in combination with certain childhood experiences, has been shown to be linked to increased liberalism later in life. The explanation for this being that those with DRD4 would seek to learn more from their friends lifestyles. This in combination with a large number of friends would mean the individual would have more experience with other people’s beliefs and cultures, thus leading to a more liberal personality.
This goes to show that although not exactly 100% definitive, we are indeed making leaps and bounds in terms of scientifically identifying the roots of certain behaviors. With respect to eugenics, this means an increased ability to categorize and select for offspring by taking account more traits on the genetic level.