Unpredictable behavior in others can be really frightening. Not that we have to be able to anticipate people’s every move, but that their behavior has to fall within a certain range in order for us to feel comfortable and safe. We have a very firm, clear idea of what behavior is acceptable under various circumstances, and when someone acts outside that range, we feel threatened. For example, a stranger does not come up out of nowhere and place a hand on your face. We would not tolerate that; or we might in a church, but not on the subway. Whether we thought it had some kind of cultural meaning to them or not, whether the touch was gentle or not, we would feel alarmed.
When driving on the freeway, we expect and need people’s driving behavior to be reasonably predictable, and we perceive an erratic driver as potentially dangerous (either directly or indirectly). In much the same way, I think we react adversely when someone appears to be behaving outside the range that we regard as normal because it means that that person does not subscribe to our codes or norms. Just theorizing here, but I think it is a natural alarm that goes off, probably even at an unconscious and involuntary level. Those commonly held codes or norms allow us to move about in the world with some sense of safety because they constrain behavior and thus serve the common welfare.
Just as with a strange dog or a wild animal, we also do not know how to assure perceived nonsubscribers that we mean them no harm, and we don’t know what they might do if they think we are a danger to them.
What’s more, someone who does not subscribe to the code is a threat to the code itself because it means that the code can be flouted or dispensed with, and that weakens the hold of the code over those who conform to it. Much bigger threat here than simple violation.
The range of acceptable behavior is in part culturally defined, which is one reason why people are naturally suspicious of foreigners. And in a multicultural society, there can be a lot of confusion and insecurity in knowing that people in your community don’t recognize your rules and that you don’t know what some of their actions and behaviors mean—you don’t know their code. Same with any subculture, and same with people who are intoxicated, and same with people who behave abnormally for mental or physical reasons. The code that protects people, the unwritten social bargain, is not being observed, and so you don’t know how they are going to behave, you don’t know how you should behave, and you don’t know if you are in danger.
This is what I think is going on. In a civilized and cosmopolitan world, many or most people get far enough past those rather primal fears and reactions to be able to meet and interact with others who are very different from themselves in all kinds of ways. We learn at least a little bit about one anothers’ customs and practices, meaningful gestures, social signals, etc., even though many of us continue to be puzzled by those things with respect to cultures that are radically unlike our own. But those strong instinctual fears of people who are not of one’s own tribe can still crop up, sometimes unexpectedly and with a vengeance.
And when it comes to people whose behavior is different not because they come from another culture or social environment but because their mental state is outside the normal range, we have no assurance that they subscribe to any rules or limits or codes at all except whatever their internal state might dictate.
I have thought a lot about the tendency to fear difference and to fear the one who doesn’t subscribe to the code because I have often been perceived as the nonsubscriber. My answer to the question is not the result of training or scholarly analysis. I am just sharing my own perception here, and my intent is to do it in a descriptive and nonjudgmental way.