What you are asking here is "is the likelihood of commiting an act of violence biologically based" and this is a question of nature vs. nurture. Is our behavior a result of our biological make up (e.g. genetics) or a result of our enviroment?

When you look at the biological makeup there are certian factors that may make someone more prone to divient acts. For example if a person has a mental illness they are more likely to harm themselves. However this is very specific to the mental illness as not all mental illness is biologically based and not all of those who are mentally ill will self harm.

When you look at nurture you are looking at what we are exposed to and how this shapes our sense of good and bad, right and wrong. This occurs through classical and operant conditioning.  As a child we can be taught that we are punished for stealing which will most likely result in the behavior of theft not occuring again. However let's assume that we need to steal to meet our basic needs, the mere act of getting our basic needs met will reinforce the behavior of stealing and will make it more likelty to occur again.

Thus nuture has more of an effect on moral based behavior, which devient behavior is considered to be, than biological nature has.

This depends on the deviant act, but it is generally true that most deviant acts have at least some degree of biological cause.

Some deviant acts are in no way criminal.  They are simply deemed unacceptable by society.  Therefore, things like sex outside of marriage can be considered deviant even today and were once seen much more in that way.  These sorts of acts are clearly biologically influenced if not determined.

Other deviant acts are criminal acts.  Even these are, in many people’s minds, somewhat determined by genetics.  Many researchers believe that people have genes that can predispose them to commit crimes.  This is not to say that biology completely determines their actions.  It is clearly possible for people to avoid acting on their biological impulses.  However, it does appear that some people are more prone to commit crimes.  They are likely to commit crimes unless they are socialized strongly away from such actions.

Thus, it is clear that many deviant acts are at least influenced by people’s genes.  It does not mean that they will necessarily act in deviant ways, but it does mean that they are more likely to do so.