There is nothing wrong with being upset by the suffering of another person. The fact that it can touch you on a personal level is a good thing.

Regardless of how I feel, what is done is done. I can't change what happened to kurdish girl in northern Iraq yesterday or what happened to a man on a Louisianna plantation 200 years ago. What I can do is learn their story, try to find out why it happened, and present that information to people who otherwise wouldn't have heard of it. If I do that faithfully, it just may prevent someone else suffering a similar fate.

If I can show the public that they have something in common with this person that was stripped of personhood based on something as menial as skin color, ethnicity, religion, or gender...then I've given their suffering a higher purpose and just may save someone else from a similar fate in the future.

Let that anger and sadness do something. If you just sit on it, then it will eat you alive.

Preface: This post is entirely based upon my views, my experiences, and my extensive reading into human violence. It may not be for everybody, and it's not very 'academic', but it's my view on this matter.

In my studies I read and think a lot about killing in battle, which is one thing, but I also am forced (for the sake of completeness and academic rigor) to look closely into other depressingly routine aspects of violence in the ancient world. Mass rape, enslavement, the killing of prisoners, the butchering of civilians, and countless and constant more 'isolated' cases of such conduct by soldiers is absolutely the norm throughout the period I study. My reading of secondary sources, and general knowledge of the huge scale of violence against 'innocents' in basically all periods of human history, especially the 20th century, has led personally to the conclusion that this sort of conduct is an inalienable aspect of human nature. It is also in my view, even more unfortunately, not simply 'evil' but 'normal' human violence that in many cases seems to be the only way to solve problems between individuals and states and has been a dominant factor in human interactions with relatively few exceptions ever since pre-historic humans starting living in small communities.

We are fortunate enough to live in a time of peace, of which there have been many throughout history, giving us all a more pacific view of human nature. The high advancement of Western society in terms of strength of institutions, rule of law, and their disproportionate military dominance over the rest of the world (for now) restrains, at least in our corners of the world, these natural behaviours. That such a thing is possible gives hope for the future, but it is the product of stable, advanced states and institutions, stable political systems, no significant external threats and a relatively settled 'world order' in most places. This can change in the future, and it is important to remember that maintaining peace can take as much resolve and constant effort as war does.

This, unfortunately, is the reality of the world we live in even today. The fact that we are rarely faced with violence, (and never on more than the individual scale aside from terrorist attacks) in Western societies means we are not particularly well adapted to coping psychologically with the violent realities of human nature. I work in a vaguely violent occupation (security in a mental health institution/emergency department with a toxicology speciality) and so I witness, am the victim of, and even inflict just enough minor violence that reading about this stuff all the time does not bother me so much, as I can understand it at least in the weakest sense. But many people who know me think my perspective is warped and unhealthy. However it helps me cope more easily with the unfortunate aspects of human nature and conduct throughout history.

That said, it routinely bothers me. I am especially sensitive to rape, which was a horribly routine (even glorified) fact of life and war in the ancient world: you can see rape heavily implied in the way soldiers physically assault women in visual depictions all over Roman victory columns such as that of Marcus Aurelius. Sometimes I have to go read about something else. I also have to accept that human nature is not as simple as 'good' or 'evil', and the same people that do great deeds can also do very terrible deeds. A modern example might be a soldier who has won great decorations for his service to his country and would be willing to die for the people he is fighting for, which is a noble thing, but the same soldier might also execute prisoners of war on the battlefield. This is a somewhat common if simplified example. The 'duality of man', as Joker puts it in Full Metal Jacket, is a reality in all of us. Our environment and physical circumstances drastically shape the balance of this 'duality', but life is and has always been a violent affair.

With this in mind, take some inspiration from the incredible achievements of the post-WWII world in maintaining peace in most parts of the world. Those parts of the world that are not peaceful have a long way to go, but their development is a painful and gradual process that you cannot personally affect. Likewise, you cannot do anything about individual crimes that occur in our society, other than to help maintain the general societal disapproval for violent acts. I would suggest that phenomena such as Unit 731 are not typical acts of violence for any period of human history, but are examples of particular sadism. Take comfort in knowing that even among violent people and in violent periods such as war between states, even in the ancient world such sadism is and was not the norm. A fascination with the macabre tends to draw us to the most terrible examples of human conduct throughout history, but the good qualities of humans are just as prominent in all periods of history even if they don't get the attention they deserve. The same men raping and pillaging in the legions would die for their city, die for their country, and give everything they have to ensure their community prospers.

Try not to focus entirely on the negative aspects of human behaviour, because if you look at the other side of our 'duality' you'll see just as many positive aspects to how humans behave. I might also suggest however that you use your knowledge of the commonness of violence among humans to be thankful for the peaceful society you live in, and let it put in perspective many of the troubles of your life. We tend to have a belief that we should be able to change things and fix things, and this is part of the reason soldiers who go overseas to fight come back traumatised when they witness terrible things that they had no power (or legal justification) to prevent. However, we usually can't stop bad things from happening. They are, unfortunately, mostly beyond our control. Think about it, but in the end try to be thankful for what you have. It's your responsibility to yourself. Try also to treat other people with respect: the most direct impact you can have on the world around you is your interaction with the members of your society. Try not to make anyone's life harder, try to help people when the opportunity arises, and you've done basically all you can to make the world a better place.

I think of humanity as a work in progress and our history as a slow crawl towards becoming a better, more empathetic, less brutal and animalistic species.

It may not feel like it when you look around the world today but we have made enormous progress as a species.

Think about slavery. Two centuries ago the idea that some human beings were inferior and could be bought and sold like animals was widespread. Today it's anathema through most of the planet.

Same with concepts like democracy, freedom of speech and religion, women's rights and animal rights. While we're still a long ways away from having those values be universal they're certainly a thousand times more widespread and accepted than they were in say 1066 AD.

Just like we look back at Chattel Slavery and cringe one day our great-great grandchildren, living in terraformed asteroids orbiting sustainable colony worlds around Próxima Centauri will cringe when they hear about things like honor killings and ethnic cleansing.

We're on an upward journey and one day we'll fill the Galaxy with hundreds of successor humanoid species who will all carry within them a deep aversion to violence, intolerance and exploitation, bred into their modified genes by the traumas we all experienced in this planet on our 200,000 year journey out of the muck.

This can be a serious concern for many of us who are active teachers. I took a seminar on the Holocaust as an undergraduate, for example, and the professor required us to submit weekly reflection journals as part of the course; about 1/2 way through the semester he decided we were all going to take a break because multiple students were reporting nightmares related to the course material.

Much less dramatic for me is the simple concern that a long litany of negative information-- people mistreating one another in general --can indeed lead students of history to lose hope in humanity. It's also true that teaching national histories can/will/should undermine the broad patriotic narratives most of us are raised on. As an Americanist who has been teaching undergrads for 25 years now, I am pretty conscious of how my courses might impact my students. While I don't shy away from negative, counter-mythological, or disturbing material at all I do try to provide some examples of positive historical narrative as well. So teaching (and learning about) topics like war, slavery, genocide, oppression, poverty, and the like will be challenging emotionally for many of us; my response has always been to look for good in the bad, or barring that, to simply take that break my Holocaust studies prof gave us back in the day.

When researching-- rather than teaching --I deal with it differently. In part, I just avoid doing serious, long-term research on depressing topics. (In fact, I tend to seek out topics that inspire me.) If I need to deal with something very negative in the shorter term, say in preparing a course or a class activity, I just strive to confine it to a fixed amount of time per day and avoid "taking it home" so it doesn't spill over into my personal life. How people can do projects on terrible things/people that require decades of investment and wallowing in grim detail I cannot say, as I've never done that-- by intent.

It is normal. However, I'd recommend balancing your reading with a "fun" topic like music or food or games. That's what I do and it helps.