Humans engage in violence ranging from one-on-one confrontations to global conflicts.

Digital Vision/Photodisc/Thinkstock

Nature, Nurture and Violence

To say violence is part of our evolutionary process is an oversimplification. Not everyone exhibits violent behavior. If humans were naturally and chaotically violent, our species wouldn't have survived for millennia.

But if we dig down, we'll find even more confusing questions. Are our violent natures buried deep within us, waiting for the right set of circumstances to come to the surface? Or do we need to learn violent behaviors from others? Do our social groups restrict our violent tendencies, or do they foster them?

Psychologists, sociologists, anthropologists and ethologists -- scientists who study behaviors -- struggle to answer these questions. We're complex creatures and there are no easy explanations. We're capable of considering our own actions. Humans can plan and reflect upon our deeds. We're able to question our own motives and consider the consequences of the things we do.

While we may all have the capacity to be violent, we may only exercise violence under certain circumstances. It's not hard to imagine two scenarios featuring the same group of people that result in either repressing violent tendencies or embracing them. In the first scenario, one of the community's defining characteristics is a stable family structure. In the second scenario, the families within the community lack stability. You'd probably guess that the second scenario would be more chaotic and violent. It would be almost impossible and certainly unethical to perform such an experiment. But crime statistics seem to indicate that communities that lack stable family units produce more crime -- particularly violent crime.

Cultural values and beliefs can also play an important role. The Gebusi tribe in lowland New Guinea isn't particularly aggressive -- the men of the tribe don't tend to form raiding parties or militia. Social interaction is marked with affection. But the homicide rate among the Gebusi is one of the highest in the world. One reason is that the Gebusi believe in sorcery and witchcraft -- killing someone believed to be practicing lethal witchcraft is permissible within their culture [source: Knauft].

There are other elements that can influence us to make us violent. Mental disorders or brain damage can affect judgment and perception. These cases are outliers -- they happen, but they're not the common experience among a community.

Within a population, certain traits may make particular subsections more violent. In a study of aggressive behaviors within a college community, researchers discovered that males with low levels of fluctuating asymmetry (FA) admitted to being in fights more than those with high FA. Fluctuating asymmetry is a deviation from perfect bilateral symmetry, and is the product of environmental and developmental stresses. The study suggests males who have greater symmetry -- and presumably fewer mutations than those with less symmetry -- are more violent [source: Furlow, et al.]. In other words, violence may be simply a part of human nature.

Our personalities are the products of thousands of influences. Some are biological and date back to before humans even existed as a species. Others develop as part of our social and cultural practices. We may never have the complete answer to what makes us a violent species. But we should always ask ourselves these questions -- if nothing else, we may find the secret to reducing violent conflict.

For more on violence and other related topics, punch on over to the next page.