You know all those “coexist” bumper stickers? They may have gotten it exactly 180 degrees wrong. From “The Geography of Ethnic Violence”:
Our analysis shows that peace does not depend on integrated coexistence, but rather on well-defined topographical and political boundaries separating linguistic and religious groups, respectively. In exactly one region, a porous mountain range does not adequately separate linguistic groups and violent conflict has led to the recent creation of the canton of Jura. Our analysis supports the hypothesis that violence between groups can be inhibited by both physical and political boundaries. A similar analysis of the area of the former Yugoslavia shows that during widespread ethnic violence existing political boundaries did not coincide with the boundaries of distinct groups, but peace prevailed in specific areas where they did coincide.
In other words, our world is comprised of opposites:
For different tribes to coexist, they must know who they are and be separated from others so that competition does not force them into ruinous postures. When competing with others, any given party is prone to discard as “unnecessary” many necessary functions in order to win the competition, which is why inducing an enemy into unnecessary competition is an effective technique.
Those who have strong ethnic identity are happiest and to have that strong ethnic identity, they need separation from any groups which might assimilate them. For the most part, people focus on the everyday and want things like society to “just work,” which includes needs they cannot articulate like having strong ethnic identity and strong borders.
In fact, we might view the desire for mental stability as the key to happiness and what ethnic identity provides most. People benefit from strong answers, not ambiguities, that tell them that they are living in the best possible way. With that, comes contentment. But in order to have that, they must erect strong boundaries between themselves and others, no matter how un-pc that is.