You may not have realised this, but it's because they are... Brahmins! No, that's not my theory - but it's the one described in an article in the Sydney Morning Herald today.
Not a lot that I can say, other than to remain in vein and point out that the Brahmins have scored most of the runs for India in this series. It also stands to reason, I am forced to conclude, that there must be a super secret by-invitation-only subset of Brahmins, who run even less than their 'ordinary' counterparts. No doubt Sourav Ganguly is a member of this sect :-)
Good thing there's some entertaining journalism doing the rounds to take our minds off what is on the way to becoming a bore-draw.