Indian Dominance of the Spelling Bee

One possible explanation:

But Nehru would have approved of spelling bees. Indian pedagogy relies heavily on rote memorization--the result of a fusion of Victorian teaching methods imposed by the British and ancient Hindu practice, in which the guru (or teacher) imparted his learning to pupils via an oral tradition. (The Victorians, for their part, regarded correct spelling almost as a moral virtue, and certainly as a caste "signifier," to use a clumsy anthropological term.)

So the act of sitting down for months with dictionary on lap, chanting aloud the spellings of abstruse words and then committing them to memory probably taps into an atavistic stream coursing through the veins of Indian bee-children. A friend tells the story of how, in his childhood, he'd had an Indian boy home for a sleep-over. He awoke in the middle of the night to find his guest poring over the host family's Random House dictionary. "I own an Oxford dictionary," the boy had said, by way of bizarre, nocturnal explanation. "This American dictionary is so different!