Again, not according to Mr Cartledge, who seems to be a (the most?) respected authority on Spartans. He is quite conservative about all his statements, especially when taken in comparison with some of his colleagues. I haven't read that widely, though (off the top of my head, his book, Tom Holland's Persian Fire, Russell's History of Western Philosophy, Graves' The Greek Myths, but the last two had almost no information on Spartans).