False polarities. The debate has long raged in and out of anthropology: Humans are naturally aggressive; no, aggression is learned. War is genetically based; no it is not. The answer is not one or the other but both. The polarities turn out to be false polarities. In these questions, there are no absolutes; everything is a matter of degree. In seeing only absolutes, one misses the critical degrees, yet it is in these degrees that lie the answers to the questions of how humanity has gotten along in the past and how we can get along in the future.
The debate, often fierce and emotional, unfortunately obscures where, in fact, scientists and scholars do agree. Few would disagree that humans are both capable of violence and capable of controlling violence. Most would acknowledge that humans sometimes live in a sustained condition of war but also sometimes live in a sustained condition of relative peace.
If human beings were as inevitably aggressive as we are often pictured, why do we not kill each other far more than we actually do? All the police in the world could not keep people from doing what comes naturally. If war is our natural state, why do the great majority of human conflicts not end in violence? How is it that human societies can live in internal peace and coexist nonviolently with their neighbors for long periods of time?
Just because we naturally eat doesn't mean we need to overeat. Just because we like sex doesn't mean we need to rape. Just because some humans like to dominate doesn't mean we need to enslave others. That aggression is innate doesn't mean that violence and war are inevitable. Indeed, there is nothing wrong with aggression in itself; primate mothers, for instance, use mild forms of aggression to teach their offspring correct behavior. It all depends on how the aggression is expressed and for what purpose.