Alyssa Rosenberg discerns them. First on her list:
Torture is wrong. J.K. Rowling’s adamant that torture and indefinite detention are morally wrong and counterproductive. Barty Crouch, Jr. is a nut, but he’s clearly radicalized and made even crazier by his experience undergoing psychological torture at Azkaban. Sirius Black is imprisoned there without a trial — can you imagine what the punitive damages would be in a wrongful imprisonment case if there were dementors involved? Bellatrix Lestrange’s addiction to torture warps her morally — and she doesn’t get any useful information out of Hermione when she tortures the younger woman at Malfoy Manor. Harry tries torturing people several times, but can’t do it, and in the end, his preference for less coercive tactics helps him beat Voldemort.
I'm not surprised as this is a core value for the English. Think of Doctor Who, another British invention who is marked by a refusal to do what villains and Americans do, i.e. torture.
The Dish 