When I'm watchin' my TV / And a man comes on to tell me / How white my shirts can be / But he can't be a man 'cause he doesn't smoke / The same cigarettes as me...
Mick Jagger, in I Can't Get No Satisfaction
We're all internally wired to feel threatened by anyone who doesn't share our values. Possibly it's a survival mechanism -- if we hadn't been that way through the ages, our species would be gone. Possibly it's a holdover from the era of tribalism, when a member of another tribe was often a genuine potential threat. That internal wiring was useful then, and continues to have some usefulness even now. But like any human trait, it has its downside.
I'll define values to be the rankings, according to their importance to us, of certain abstract concepts we carry in our minds. A few examples of these abstract concepts: personal independence; family; religious beliefs; control of others; sexual pleasure; interpersonal peace; responsibility; sobriety; chastity; personal recognition; being entertained... Each of us ranks these concepts, and many others, from most important to least. (As you read that list, you probably mentally dismissed some of them as being unimportant to you, while picking out one or two as being central to your life.) Each of us does this ranking in our own way, in response to our life experiences, our intrinsic personalities, and other factors all working together, and the end result is our system of values. As soon as we perceive that someone in our lives seems to have values significantly different from our own, we feel a threat from them. That includes their presence on television or the Internet, completely removed from any possibility of physical contact with us.
Since no two people have exactly the same values, the question arises: just how different do two people's values need to be before the alarm goes off and the defensive adrenaline rush begins? Conveniently, values themselves are the measure that allows precisely those sorts of lines to be drawn. If the values of Sam differ from those of Mike in relatively unimportant areas (the importance to each of them being weighed, of course, by their sets of values), Sam and Mike can get along with each other well enough. But if Sam's values tell him his differences with Mike are important, then from Sam's point of view, Mike is an enemy worthy of mistrust at the very least, and an imminent threat to be battled, if Mike should approach too close.
Mike may not see it the same way, and may not even realize that Sam is threatened by him -- perhaps Sam's way of dealing with threats is to take on protective coloration that allows Mike to think of him as a kindred spirit. If Mike doesn't push it, that can go on indefinitely.
You, yourself, may be a laid-back person who doesn't feel bothered (or you don't believe you feel bothered) by another person's differences from you. That doesn't mean your alarm doesn't go off. What you do about the alarm or what you consciously feel about it depends on what sort of person you are, which in turn goes back to your values. Also, you may be surrounded by people whose values are sufficiently similar to yours (there is a strong geographical component to this) that you rarely run into the problem. But I'm willing to bet that, when your alarm does sound, at the very least you feel uncomfortable.
Politics is an obvious source of values threats. Since any national government is very powerful, there's no surprise in the fact that we'd like to see it run by people who think like us. Political parties form exactly for the purpose of increasing the power of people who have similar values, and party members are conscious, and worried, that there are people out there who don't share their values. The fear of opposing parties spreads out to swamp the complexity of political beliefs: if you have a political enemy, he must be an enemy in every way. Every facet of his beliefs must be wrong. If you are a Republican and love America, say, then any Democrat, being of a different party from you, must evidently then hate America. The more shameful your opponent becomes in your mind, the easier it is to maintain the needed degree of hate for him.
Cultural distinctions are another category of values and a source of values threats, unique in its own way. (Racial differences occupy a sub-category within this category.) We tend to regard members of other cultures with some degree of contempt, often finding humor in the mores of other cultures. The contempt may express itself in bitter ridicule of the affronting culture. The cultural difference may be something as inconsequential as standard dietary tastes. People in Korea eat dogs and we don't? We make jokes about the Koreans. People in India don't eat cows and we do? We make jokes about the Indians. On the other hand, if someone in our cultural group has been attacked by a member of another group, the humor disappears, as the feeling of general threat spreads beyond the person who was attacked and covers the entire group.
Religious beliefs and resulting sensitivities are at or near the top of many people's values rankings -- the belief that your adherence to certain precepts will determine your environment eternally is a strong motivation for attaching critical importance to those precepts, generating an assurance that you are right and everyone else is wrong. Some people feel the values threat from adherents to other religions so strongly that they feel a need to murder anyone whose practices violate their beliefs.
Having brought up the subject of religious intolerance, I want to make it clear that no one religion has a monopoly on virulent hate towards followers of other religions. At the present time, many Americans (and Europeans) have the impression that there is something uniquely paranoid in twenty-first century Islam that has turned many of its followers into a worldwide threat of violence and terror. (Or that they always were.) But it is important to acknowledge that there is nothing unique, in that sense, about Islam. To the extent that our religion (or lack of one) is an important value in our lives, all of us, not just Muslims, feel threatened by anyone who disagrees with us and feel a motivation, sometimes acted upon and sometimes not, to fight them -- regardless of whether our religion itself tells us, in so many words, not to do that. For many, the religion itself is the value, not anything the religion actually says. Many have been attacked and even murdered in the name of religions of peace -- note the plural, "religions." I'm not talking about a specific one.
An example: I was appalled by a picture in Newsweek magazine, years ago, that showed a very striking image of hate. The picture was of a group of terrified, crying schoolgirls and their frightened parents running a gauntlet of vicious, snarling adults throwing stones and bricks at them. The girls' crime was being Roman Catholic. They were simply trying to get to Holy Cross Primary School in Belfast, Northern Ireland, and unfortunately they had to pass through Protestant territory to get there. That is, Christian children and their parents were being physically, brutally attacked by Christian adults for not being the same kind of Christians. See Wikipedia: The Holy Cross Dispute. The reason this image from Belfast really stuck in my mind permanently is that this issue of Newsweek was delivered to my mailbox on September 11, 2001, the very day the Belfast story was suddenly pushed to the background of world attention by another, larger story of religious hatred.
Protestants and Catholics in Belfast, Sunnis and Shiites in Iraq, Muslims and Jews in Jerusalem... In these and in so many other places, when populations of believers in (even slightly) different religions come into close contact, each side feels a threat from the other because their highest-priority values are different. In the above-named examples, the danger has often been real enough in the past that feeling at least some degree of caution and apprehension is a reasonable response. But the threat is felt regardless of whether the danger is real or imagined.
There is, for example, nothing surprising about the current outcry, from the far religious right in the U.S., about a "war on Christianity" within the country. In a time of evolving cultural values, people whose values aren't changing will always feel threatened. In this case, even something as innocuous as being wished "Happy holidays" during the Christmas season, a well-meaning attempt to make the good cheer of the season more inclusive, is, somehow, seen as a threat.
I have read claims from people (usually atheists) that religion has been the cause of all wars. The claims have always struck me as ludicrous, since they require ignoring a large number of huge and consequential wars that started for reasons with no connection with religion. But I do feel it's safe to state that a significant portion of all wars result from clashing cultural values. By "cultural values," I mean those values shared in general by the inhabitants of a geographical area, and war can easily break out between two different cultures that feel threatened by each other. Even differences in language, an example of a cultural value, can lead to warfare -- look at Ukraine. And since religion is so often a top priority among cultural values, then yes, it does often lead to wars.
Can anything be done about this? Well, no, of course not. This values-threat system has been with us since the cave man days, when members of one tribe would attack another tribe, just because they were another tribe. The human race survived that era for at least a couple of reasons: (1) There's a limit to the amount of global damage you can do with a club, and (2) the mistrust of others who are not like you has some advantages -- being unlike you, they may be a legitimate threat to you, and it's sometimes a lucky thing you had an internal alarm allowing you to perceive the threat. That is: in Darwinian terms, this reaction to others has survival value. Unfortunately, in the twenty-first century, point (1) above no longer holds: with atomic weapons, biological weapons, chemical weapons, the aptly named "weapons of mass destruction," very small groups can now take major steps towards destroying the entire population of the planet, and point (2) only applies when the reaction to values threats is primarily defensive in nature. Unfortunately, there will always be people who act pre-emptively against real or imagined threats to their systems of values, and it is probably only a short time until someone disposed to such action acquires the power to do it in a global way. When it happens, our final thoughts can be: Well, at least they were wrong.