Back in school (I went to an Indian school in Kuwait till the beginning of 11th grade), the Indians would say that Bengalis were smarter because of the fish we ate. Based on this article [hat tip, marginalrevolution.com], one can now claim that it might actually have to do with how, culturally, it’s rude to look someone in the eye for too long when interacting with them. (This cultural trait probably generates some confusion (and some suspicion?) when Bengalis come to the West.)  

On the other hand, shifty-eyed or not, we are a people with an extremely short historical memory. Right, Jajabor?