Why Vegetarians Are More Intelligent Than Meat Eaters

Correlation doesn’t imply causation. People with higher IQs self select for more education and are exposed to more eco-philosophy as a consequence.

Also, people with higher IQ self select for higher paying jobs and are better able to afford the more expensive vegetarian lifestyle.

Also, IQ is linked to better nutrition and educational opportunity and having parents of a higher economic class with likely higher IQ so again the higher in economic standing your parents are, the more likely you will be presented with environments that will teach vegetarianism.

(That said, as a high IQ person with all those advantages, I still eat meat some of the time.)