Why do we fear the unknown more than the known? That’s a larger question than I can answer here (not that I’m capable anyway), but it probably has to do with the heuristics — the shortcut guesses — our brains use to solve problems, and the fact that these heuristics rely on the information already stored in our memories.That's probably right. But when I read Dubner's post, I immediately thought of another factor: hostility toward outsiders is instinctive because it can help communities bond.
And what gets stored away? Anomalies — the big, rare, “black swan” events that are so dramatic, so unpredictable, and perhaps world-changing, that they imprint themselves on our memories and con us into thinking of them as typical, or at least likely, whereas in fact they are extraordinarily rare.
This idea actually grew out of an attempt to understand altruism. Altruism is something of a puzzle to evolutionary biologists - the easiest thing to assume, under a "survival of the fittest" framework, is that selfishness is always the winning strategy. Yet again and again in human and nonhuman societies, we see examples of altruism, in which individuals help each other without immediate repayment. Societies in which everyone is altruistic should be able to out-compete societies in which everyone is selfish - but a single selfish person in a mostly altruistic society can out-compete her neighbors, make more selfish babies, and eventually drive altruism to extinction. So, if you can come up with a way to make altruism stable in the long term, you've got a good shot at publishing in Science or Nature.
One such paper was published back in 2007. Co-authors Jung-Kyoo Choi and Samuel Bowles noted that tribal human societies spend a lot of time and blood in inter-tribal wars, and wondered if what they called parochialism - hostility to outsiders - helped stabilize within-tribe altruism [$-a]. They built a mathematical model of competing tribes, in which individuals within those tribes had one of four inheritable personality types: parochial altruists, tolerant altruists, parochial nonaltruists, and tolerant nonaltruists. Parochial altruists were something like the medieval ideal of a knight, willing to fight outsiders and die for the benefit of others in their tribe. Parochial nonaltruists weren't willing to risk their lives for others; and the two tolerant types were, well, tolerant of others.
Photo by Lawrence OP.
Photo by Lawrence OP.
As I described above, nonaltruists were favored by within-tribe competition: altruists all contributed toward a common resource pool, which was shared among the whole tribe. So nonaltruists got a share, but didn't contribute, which benefits them but is ultimately bad for the tribe. Tribes that fought other tribes and won could expand their territories and take the losers' resources. On the other hand, if tribes interact peacefully, the tolerant individuals - and only the tolerant individuals - received a resource reward. (Is this putting anyone else in mind of certain new-school German board games?)
Choi and Bowles found that their model led to two alternative stable kinds of tribe dominated by either tolerant nonaltruists or parochial altruists. This is almost too tidy, because it looks like a dichotomy between peaceful-but-selfish "moderns" and mutually-aiding, warlike "primitives." Yet tribal societies really do seem to be more prone to a certain kind of war (more like feuding, really), as Jared Diamond discusses in a 2008 essay for the New Yorker [$-a]. And, even in our modern, globalized society, we are immediately and instinctively suspicious of - hostile to - those different from us. Commenting on Choi and Bowles's paper in the same issue of Science, Holly Arrow called this the "sharp end of altruism," [$-a] and wondered how to tease apart the apparent association between altruism to neighbors and hostility to outsiders.
The most obvious option may be to expand our definition of "neighbor." In a world where an Internet user in Malaysia can see (selected portions of) my ramblings on this 'blog, maybe I'm less of a stranger than I would be otherwise. That's not much, really, but it's a start. The wonderful thing about being human is that, understanding our own tendencies, we can seek to overcome them.
H. Arrow (2007). EVOLUTION: The sharp end of altruism Science, 318 (5850), 581-2 DOI: 10.1126/science.1150316
J.-K. Choi, S. Bowles (2007). The coevolution of parochial altruism and war Science, 318 (5850), 636-40 DOI: 10.1126/science.1144237