I dated an Israeli woman a few years ago. It didn't work on my part because I really wasn't attracted to her enough. But in terms of thinking, we were fairly close. She was very socially liberal. In fact, her last long term relationship had been with another woman. She was pro-abortion, pro pre-marital sex, very bright, very open minded.

But she wouldn't eat pork. And of course, it came up almost immediately in our relationship, because we ate together a lot. Realistically, she was bright enough to know that there is nothing wrong with pork. It's good meat. You can cook it a variety of ways, and lots of people eat it. And it wasn't like she was vegetarian. She would eat beef or chicken without hesitating.

So why was the pork thing so important to her? If she was liberal on all sorts of things? Willing to have a open long term lesbian relationship? Not a vegetarian. Aware that pork was perfectly acceptable meat?

Identity. The pork thing was how she connected with her cultural past and differentiated herself from those who did not share it. And it's like a perfect way to do that. It's one of those things that will come out just about any time she sits down to eat with people who don't share that identity.

Food is just a really good way to separate to yourself out. In Asia and Europe, you can see it all over. Moslems/Hindu - Moslems - no pork. Hindus - no beef. Moslems/Christians. Moslems - no alcohol. Christians - Alcohol central to religious ceremony.

In modern culture, we see it to some degree as well. While in radical Islam, the ban against alcohol use remains very strong, prohibitions against the use of other drugs are not regarded as being as sacred. Look at the Taliban in Afghanistan. They had no problem with letting their farmers grow opium. Morocco is the number one producer of marijuana. Whereas in the west, we know alcohol is even more dangerous than marijuana, but it is part of our culture.

That sense of identity is important to people. It creates belief clustering. The more radical versions of belief get more attention and more focus. People who join groups with strong differences gain that sense of identity, while those who are in the middle don't. Christian fundamentalists get all the attention, as do Islamic fundamentalists. These tend to attract followers who gain the reward of feeling like they are part of something special and different and apart. "Come to our wishy washy church. We believe in God and stuff." vs. "Follow strictly the way of the lord or burn in the pits of fiery hell."

So we cluster, and clump, and focus, and form lumps on the landscape of beliefs instead of undifferentiated masses of people with patchworks of practices. It's a natural human tendency, where sometimes the central point of the clumping is not so important as the fact of the clumping itself. Like with pork.