Hey! According to the BBC, a study has shown that high IQ correlates with vegetarianism. The study gave IQ tests to a group of over 8000 children in the 70s, then went back and took their demographic information when they hit 30. The average IQ of the children who grew up to be vegetarians was 5 points higher than the average IQ of the non-vegetarians.
Some caveats: First, the demographic data gathered in the second stage counted everyone as a vegetarian who claimed to be one, rather than defining a criterion for vegetarianism and determining who was one based on that. This makes sense, because there are a great many flavors of vegetarianism, so to speak. This means that people who eat meat or fish, but who self-identify as vegetarians, are counted as vegetarian. In any case, it doesn't seem to have made much difference in the results.
Also, it's hard to tell how much of a correlation vegetarianism specifically had. Apparently, a good amount of the IQ differential could be accounted for by class and educational differences. When class and educational difference are controlled for, however, there is still apparently a positive correlation between vegetarianism and higher IQ. They don't give the post-control values for that, though.
I like the quote at the end from Dr. Frankie Phillips of the British Dietetic Association: "It is like the chicken and the egg. Do people become vegetarian because they have a very high IQ or is it just that they tend to be more aware of health issues?"
First, it's an interesting choice of simile, given the topic. Second, I'm not sure if he's using Chicken-and-Egg right, here. Chicken-and-Egg tends to be "Does A cause B, or does B cause A?" Here, he's asking whether High IQ causes Vegetarianism or whether High IQ causes Health Consciousness, which causes Vegetarianism. So his question is more "Does A cause B directly, or does A cause C, which in turn causes B?" The proper Chicken-and-Egg formulation of the High IQ-Vegetarianism correlation would be "Does having a High IQ cause you to become Vegetarian, or does becoming a Vegetarian cause you to have a High IQ?"
