Does Genetics Determine BehavioR?

A couple of friends of mine ,on two different recent occasions, have stated to me that they believe a child possesses behavior patterns carried over by genetics of their parents or other direct blood-line relative. Both of these conversations involved a mother/father that did not raise the child, and was not part of the child's social environment.

In one scenario, the child, a female, now twelve years old, was raised from an infant by the grandmother. This woman contends that even after all of these years of teaching the child morally acceptable behavior (good manners, honesty, hard work ethics, etc…), the child is a true rebel against society and continuously gets into fights, gets suspended from school, has been in court for shoplifting, and has awful behavior in general. She (grandma) says, that no matter how much love, understanding, teaching and discipline, the child has received, her behavior only worsens, and there is an imminence of a troubled life ahead for her. The grandmother says these behavior patterns are indicative of her own daughter-in-law, who gave up the child, and that genetics is the culprit.

The second conversation was similar, only that “child” is a forty-two year old mother of a three year old. She was just caught in a retail scam stealing merchandise, not long after she was involved in a domestic dispute, where a man was badly injured by a beating. According to my friend, this woman continuously gets into trouble, and was raised by a very respectable aunt, who took her in at an extremely early age. This friend also noted genetics as the problem, stating that the real mother was also always in deep with mischief and mayhem.

These two conversations got me to re-evaluating my own belief that genetics only play a part in the physical make-up of an individual, and not the behavioral patterns. Both of these children had no genetic ties to their respective surrogate parents. My mother however, had eight kids, and only one was cruel to animals, rebelled against society, and landed in jail more than once. Did the genetics skip seven and land on eight? Was it my mothers' genetics or maybe my grandfathers?

I find it a little hard to comprehend that a learned behavior such as stealing could be caused by a genetic root. I was also amazed that one of my conversations was with a highly degreed social worker, and behavioral specialist.

I would like some opinions on these questions: If a child had the genetics of corruption (for lack of a better term), and was raised by one incorrupt individual without any outside influence (no TV, no video games, no socialization) except educational reading material, do you think the child would exhibit or be prone to socially deviant behavior or corruption, if introduced to society at the age of twelve, or even six? Would it be a genetic factor if they did exhibit bad behavior? Does positive learned behavior over-ride negative genetics? Could this all be spiritually related, and have nothing to do with genetics or environment?

I think most of us would agree that if one would abuse the aforementioned isolated child, it would come to know abuse as “normal” and emanate that behavior pattern. Why would the result be any different if the child is only exposed to love, warmth, kindness and proper discipline? Yet, with my two friends, this does not seem to be true. Of course in their scenarios the isolation factor is missing, which again points to a social interaction determinant, not genetics.

I suppose there may not be a cut and dry answer here. The human mind and body is so complex in all of its workings. All of these factors may play equal roles, or maybe there are some people more susceptible to “bad” genetics than others. Maybe there is a gene that actuates another gene in the brain, and that gene is simply “missing” in some people?

For me, I find the role of genetics in bad behavior a weak link. The probability seems slim to me, if only remotely possible. I am truly interested in the feedback of others here, and any information sources linked to the subject. Thank you.