The Economist has already shown its interest in following the fascinating recent scientific work about the origins and functions of human religiosity. This week’s article on the subject, “Praying for Health,” brings up challenging questions both for the study of religion and for the study of conflict.

What the article reports—that religions have served to protect people from infectious disease—is by no means a new idea. It is positively dogma, in some cases. A rationalist Jew recently told me that the whole point behind the Kosher laws is to prevent infections from food. God as doctor, Moses as nurse, I suppose. This article goes a step further, and generalizes. It found a statistically-significant correlation: countries with more infectious diseases also have more religions. The idea is that forming new religious communities seems to be some adaptive attempt to contain disease. Because religion limits who a person can hang out with and cross genes with, it creates little zones of quarantine that may help to slow the spread of infection.

Of course, there are real problems in a study like this—what counts as a religion being the worst of them. Some religions have more porous borders than others, and there are always religions within religions. Not to mention the difficulty of distinguishing religions from non-religious communities. While the correlation is significant, it may be hard to make any definite statements about religion, as such, from it.

What can be said less problematically, though, is that the study points to a benefit of human conflict. In the peace and human rights discourse of which I am very much a part, we readily assume that peace is always preferable to conflict and unity is always preferable to discord. We tend to jump for joy whenever cross-breeding happens because it is a breaking down of borders. But, this study seems to suggest, there are evolutionary benefits for humans as a whole to being at each other’s throats.

Evolutionary benefit, however, is not the same as moral benefit. Even if conflict has helped to protect the human race, I hold it as true as ever that no war has ever been won. Rather, it points to the fact that the greatest warlords—and the greatest peacemakers as well—are in some respects pawns of processes that they don’t comprehend.