Why Do We Murder?



Christopher Ebbe, Ph.D.    6-15

ABSTRACT:  Our human characteristics that can result in murder and other killing are described, along with the implied changes in upbringing, customs, and interactions that could reduce the murder rate.

KEY WORDS:  murder, killing, hatred

Every mass killing arouses discussion about why such a thing could happen.  The reasons for murder and killing in general are complex but not really complicated.

  • Groups vie for territory.
  • Individuals do not value all other persons equally, so that those less valued can more easily be killed to accomplish other purposes (survival, material gain, feeling better).
  • We react explosively (paroxysmally) to sudden threat, which can result in emotional escalations that ultimately lead to killing.
  • We anticipate the future, which is usually adaptive but can sometimes lead to anxiety and worry about future happenings and outcomes that are sufficiently severe and long-lasting to prompt in some cases murder to alleviate the anxiety (e.g., pre-emptive war).
  • We want to be treated decently and fairly, and when we are not, it sometimes results in payback or revenge behaviors involving killing others.

We can identify behaviors that if changed would lead to reduced rates of murder and killing in general, but because they would take some time and effort or would require giving up some of our freedom, we don’t change.  Much of this stems from our societal assumption that people should individually take responsibility for their actions, and when they don’t, we criticize them or punish them but continue to expect all people to take responsibility.

Evolution (or a creator) seems to have endowed us genetically with several characteristics that have been by and large adaptive for the growth of human populations even though they have also resulted in human beings sometimes killing each other.  Chief among these is the ingrained tendency for members of a group to violently resist the loss of a group’s territory, since loss of territory means less resources for the group and therefore less ability to keep current members alive.  Competition for territory, both resisting its loss and seeking more of it (to better support current populations or to alleviate anxieties over resources), have affected all human groups.  This is the primary cause of wars between groups (although war can also occur for purely psychological purposes, to reduce feelings of threat or to reduce fear and anxiety).  This is the one category of killing for which killers are not viewed as miscreants but are praised for acting honorably for the sake of the group.

“Crimes of passion”—almost always instant reactions to discovering infidelity—are also excused by the laws of a number of states, as if that threat or insult was understandably great enough to justify killing.  Additionally, most states recognize that there are persons who are “not themselves” by reason of mental disorder and are therefore not responsible for killing in the same way that “normal” people are.

Another contributory human characteristic is our narrow vision of who is important to us.  Most people have loyalty to and to some extent refrain from killing family members or good friends (unless of course those persons have betrayed or significantly harmed the murderer).  This makes all other people less “human” to the murderer (persons from another tribe, another city, another gang, another country, another race), and this makes it easier to kill them when a supposed justification arises.

The third human characteristic that can lead to murder is our genetically-determined frightened and defensive reaction to sudden threat.  It has helped us individually to survive that we react suddenly and violently to threat, because in most cases that reaction does the most to frighten the threatener (animal or human) and thereby prevent us from being harmed, but our fear and confusion may be result in disruption and chaos sufficient to result in our killing the threatener or the threatener killing us.  Another example would be killing someone who disrespects or challenges one, which one feels is necessary not because of any feeling of shame, etc., from the disrespect but because of the threat of loss of status that would occur if one does not “defend oneself.”

These human characteristics are understandable to us, and by and large they have enabled better individual and group survival for human beings.  However, because of our unusual brains (unusual among earth organisms), we have some capacity to predict future events, and we spend time and energy fearing and worrying about some of these predictions, which results quite often in efforts to change others (or circumstances) so that we can stop feeling fear and worrying.  We may even be willing to kill another person who poses a potential threat, so that we can stop worrying about it.  This dynamic is seen in pre-emptive wars, in which one group attacks another because of their fear of them (viz., the U. S. attacking Iraq; Germany attacking the rest of Europe).

A fifth human characteristic that leads to murder is our human cognitive ability (more for some people and in certain circumstances) to guide our behavior with respect to others solely by our thoughts while blocking our usual emotional reactions to other people (including empathy).  This ability makes it easier to go to war without any concern about the damage that will be caused to others (and to one’s own warriors), and it allows criminals to kill solely for their own short-term benefit (killing someone because they “know too much” or when it is convenient but not necessary to kill (as when an unresisting car driver is killed in a car-jacking).  One example of such persons, who have no developed sense of conscience or empathy for others, is the “psychopath” or “sociopath.”  These persons do a considerable proportion of the killing that goes on, but they very rarely do mass killings.

A final key characteristic of human beings that can lead to murder is our desire for or insistence on being treated fairly and decently.  Any mistreatment can be seen as a reason for an aggressive response that goes beyond our initial defensive threat reaction and aims to harm the harmer.  (The centrality of the concern for fairness for human beings is illustrated in the concept of a Final Judgment in Christianity and Islam and the popular notion that one’s karma determines one’s future life.)  Small children all react “naturally” to harm by attempting to harm back by hitting, and this reaction can be either moderated or expanded as we grow older, depending on our conscience development (or lack of it).  If the harm is great enough, or our sense of fairness and appropriateness is sufficiently violated, any of us can be motivated to harm the other person sufficiently to in some cases kill him or her even if we don’t consciously intend that.  How we view the seriousness of the harm we receive is an individual matter, with wide variation.  Some people will attack murderously in response to an insult, and some will only attempt to harm when they or a loved one are directly about to be killed.  Sometimes the person killed has not directly harmed the murderer, as when a person disappointed in a legal outcome kills the opposing counsel.  “Shaken baby” deaths fall in this category as well; the shaker feels so harmed or inconvenienced by the baby’s crying, etc., that the aggressive response seems justified at that moment.

This inherent potential aggressive response may only be triggered after a series of harms, and it may be triggered against a person who did not directly cause the initial harm.  This is the source of much of “the sins of the fathers” being visited upon the current generation.


Using the above characteristics, it is possible to “understand” why murders occur, even though we may still be amazed at why a given circumstance would cause that behavior when we ourselves believe that we would have reacted differently in the given circumstance.  We have the greatest difficulty grasping why mass murders occur, because in most cases it does not appear that the persons killed could have directly harmed the killer and therefore generated enough anger to result in the killing.   From the mass murderer’s point of view, however, he has been mistreated by so many people that he holds the whole group (society) responsible.  Such mass murders are usually meant to be statements to all about how much the mass murderer has been harmed, as well accomplishing revenge (“evening up the score”) to make things seem “fair” again.  Most of these harms may seem small to us (teasing, bullying, social rejection, social ostracism, degradation or insults to one’s basic worth), but to the mass murderer, most of whom feel socially unable to redress those matters directly, the accumulation of them seems huge and seems to add up to enough to justify murder.

You might have difficulty believing that a series of small insults and minor harms could be a justification, since those provocations all seem small or “normal” to you, but if you could experience the emotional pain that they have caused the murderer, you would see it differently.  Even though we don’t allow this to be a legal justification for murder, we can appreciate it empathically.  You may even reject the idea that this could be the main reason for mass shootings, but that is because you aren’t willing to believe it, for it is in fact the main reason behind most mass shootings.  Our society makes a fetish out of being left alone to do what we want, which is not a bad thing in itself, but when it results in the isolation of those who are “different,” this just gives those persons even more reason to resent being isolated and neglected.  These emotional issues are touched on in the media discussions after every mass shooting, but we don’t change our behavior?

So, killing occurs because (1a) the group feels threatened; (1b) the individual feels threatened; (1c) the individual feels harmed; or (1d) the individual views the victim as unimportant and feels none of the “normal” empathic responses that most of us have to others; and (2) the individual’s conscience and appreciation for the value of others’ lives are not strong enough to prevent the murderous reaction.


There are a number of things that we could do as a society to reduce the murder rate, although we are not willing to do most of them.  We have done about all we can in the way of training children in how to treat others through standard socialization by parents and societal institutions and in punishing or threatening to punish people to get them to conform, and these traditional methods have resulted in the murder rate that we have now.  If killing is to be reduced, other methods must be tried.

1. We could think more carefully about military actions before we undertake them as a group.  If commanders and lawmakers had a ritual of seriously imagining going through the weeks and months ahead of having their sons, friends, and neighbors die in battle or be maimed for life or ruined psychologically, as well as imagining paying for war (not borrowing for it) and thus reducing the ability of the government to meet citizens’ needs, they might be slower to declare war or deploy troops.  They might also be more reluctant to use military force simply to further our economic interests and use it only for actual defense.  Trying to keep the world the way we want it is not “defense.”

2. Fewer people would be murdered if more of us viewed every person on the planet as having basically equal fundamental worth.  This would extend the general disinclination to murder family or friends to other people as well.  Thus, the robber would be less inclined to kill his victim than he currently is, because he would see the victim as having some worth instead of as simply someone to rob or as someone on whom to “take out his feelings.”

3. We could reduce the immediate access to guns that so many people have.  If people had to put forth some effort to obtain a gun before they could kill, that delay alone would prevent many shootings.

The idea that many seem to have that having more people carrying guns would reduce the amount of killing (bringing the “mutually assured destruction” concept of the Cold War to our streets), seems particularly irrational, if for no other reason than the fact that every time one side in any conflict (i.e., criminals vs. “good guys”) figures out a new way to force the other side to behave as it wants, that other side works to figure out a new way to overcome that new impediment (the definition of an arms race).

4. Modern life is so stimulating (smart phones, e-mails, media) that it pushes people toward being more reactive (and also less proactive and less planfully reactive).  Learning to be more calm (which might even require some withdrawal from our stimulation) would make us less likely to respond to things in ways that occasionally can stimulate violent reaction from others (e.g., “flying off the handle” explosively and scaring a person with a gun into shooting us).  Additionally, modern social media push us to respond quickly and without thinking, so training ourselves to pause more of the time before responding and to think about our responses before we respond would also help us step out of the cascades of stimulation that sometimes result in violence.

5. We could manage our fears and anxieties better by learning to see things objectively as well as personally and by learning to be more accepting of human life as it is, as opposed to how we would like it to be.  Accepting that life inevitably involves problems and setbacks could allow us not to be so upset about these things but to work calmly to make things as good as we can make them (and then live calmly with the result).  This would reduce the tension level in us which would prevent some killing that results from raised tension levels on the part of everyone and killing that results from more people reaching their “breaking point” than would be the case if their tension levels were lower overall.

6. We could identify young people who show serious lack of empathy or appreciation for the value of others, and require them to participate in educational and therapeutic programs that address those serious deficiencies (and hopefully to gain greater emotional appreciation for others).  In our society we expect everyone to regulate their own harmful behavior, but these individuals who lack empathy or appreciation for others will not do that in a normal way without intervention.  Even if the programs do not change the recipients’ views of others, they would make it more clear to those individuals that harming others is more serious than they naturally realize.

7. To reduce killing that results from people feeling severely mistreated, we could work together to promote and apply some simple moral and ethical principles in our daily lives, rather than only listening to sermons about them in church.  Honesty, responsibility, and taking care not to harm others by our behavior would improve our communal lives immeasureably, but we resist doing this.  Everyone would agree that these three moral principles are appropriate, desirable, and would improve our lives and reduce the number of killings (morality isn’t just about abortion and gay rights!), but many people don’t want to give up their “rights” to lie, cheat, and harm others (within the limits of the law) in order to get what they want.  This reluctance is what would have to be identified publicly (ad campaigns?, individually “calling out” in a nice way persons who are harming others on purpose (lying, cheating, insulting, controlling, dominating, putting others down, etc.)?).  You could dedicate yourself to living by these three principles every day in every interaction you have with others, and you would thereby help to reduce the amount of pain people cause each other and thereby to reduce the number of angry outbursts that result, some of which result in killing.

We could become a more caring community, by paying positive attention to those who are “different” or outcast.  Most of these persons will not kill anyone, but a few may.  In almost all cases, most of us avoid these people, because we “don’t have time” or are afraid of them or are uncomfortable around them.  Spending a few minutes talking with these persons or engaging them in something valued (yardwork, helping others with a project, joining a group like Boy Scouts) can go a long way toward assuaging the loneliness and pain that such persons often feel.  Mental health professionals and social workers could exert effort to allay the fears that most people have of those persons and educate the public on how to talk briefly and pleasantly with them.

We could become “better people” ourselves, by aspiring to treat everyone better than we do.  Instead of putting ourselves first all the time, we could adopt the principle of seeking for all of our behavior to not only benefit ourselves but also benefit others at the same time (or at least not harm them).  Our individualistic society points us toward taking care of only ourselves and expecting everyone else to do the same, but this leaves many of us lonely and empty, which could be different if we considered others to be like us and part of our group.  This consideration might apply particularly with regard to shootings at work, where the perpetrator feels misused or abused (whether or not that is “justified” in your view), and where we could avert danger by showing our concern, especially if we have cultivated a positive relationship with everyone at work already instead of only at that moment.

We could alter our instinctive reaction to murder to shun the accused (or the convicted) and get as far away from them as possible, acting as if they were perhaps not even human.  In fact, they are pretty much just like us (except for the psychopaths), and an understanding attitude with some determination to change ourselves or the environment in ways that could have prevented the murder would reduce the likelihood of more of the same.  (Statistically, murderers rarely kill more than once, so a positive attitude could help murderers to regain a useful life, and it could make it more likely that future murderers, particularly mass murderers, would be seen and approached helpfully by other citizens.)