Ever since I heard the story of crabs in a bucket — that no crab can escape because the others pull it back — I’ve been intrigued by how much we humans resemble them. Why do we do the same? Why pull others down when they try to climb up?For years, I couldn’t find a satisfying answer. Not until today. Now I know that both crabs and humans are tied by the same number — the less of magic and more of tragic number — Ten. Crabs have ten cla...