There may be two reasons for such a preference or proclivity. Both are based on human nature but different aspects of it. The first one is an issue of gender and gender-related actions. Society portrays and enforces the stereotype of the strong testosterone-driven masculine force, whereas the caring, intuitive and peaceful attitude is attributed to the meek and soft image of the female. This has repercussions on various actions of society and in most cases, religion has been used as a means to propagate such messages in implicit and explicit manners.
The second reason is linked to the realities and facts of human nature. There are some tendencies that reveal our angelic side, while others show that we have demonic capacities as well. It seems to me that war and aggression are more natural responses since it costs us much more effort to preserve and make peace. It is easier to hate and hold a grudge than to forgive and forget.
This general human tendency may be attributed to the dark forces within each of us that Freud called the id, a reservoir in which all our frustrations are stored and hid. It is like the basement that fills up and is cluttered with litter and unwanted junk and that we tend to avoid and sidestep for the very same reason.
Naturally, there is also the element of society and upbringing. Violence is unacceptable and frowned upon. Tantrums may be a natural outburst and release of anger or boredom, but they are heavily criticized. Violent acts in school are not tolerated and censured and other aggressive acts are met with strict disciplinary action. It is our conundrum where we attempt to still and counteract violence with even more violence.
Freud states that it may be of little use to look the other way, to pretend all is well and quiet on the Western front and to ignore the mounds of junk building up in our cellar. Violent impulses if not given expression, through catharsis at least, will go underground and lurk and fester there unbeknownst to us. We might surprise others and ourselves with sudden outbursts that may seem untypical, out of place and out of character for us.
In such a society where peace is on one hand held up as an ideal but is in reality enforced on various levels through efforts that do not preclude aggression, peace becomes an inverse form of violence. Peacekeeping forces waving their guns and bringing about peace through violent means make the achieved end of peace doubtful. Lasting peace cannot be created through the power of force.
On the other side of the spectrum, peace activists who oppose war through violence run themselves into a web of ideological contradictions. Religions that use bellicose language to achieve peace or paradise are doing nothing but fan the waves of violence and hatred. And all those who hate nothing but hatred still demonstrate lingering sparks of hatred.
What can be done then? The first thing we can do is to accept that violence is a part of us; it is around us as it is within us. It can be stifled for a while but it cannot be extinguished. There are different ways of venting violence, and we would have to find those that cause the least amount of damage to ourselves and others, such as sports or self-expression through the arts.
Moreover, we need to practice peace on a daily basis. It should not be an empty word or promise nor wishful thinking. It needs to be much more than an attitude. We would have to practice peace at any possible moment. We need to find peace of mind within ourselves. And more importantly, we need to be at peace with the violence that is smouldering within.