I always thought that this wouldn't have worked. The thing with the hats I mean. I think the master has to give an item of clothing to the elf directly; first I was going to say that he/she has to intend to set the elf free, too, but then I remembered Mr Malfoy, Dobby and the sock. Mr Malfoy obviously didn't want to set Dobby free, but he gave him the sock directly.
To free a house elf, you give them clothes. But house elves do all the work in the house. Does that mean that they can't wash the clothes from their masters without freeing themselves?
Also does the item of clothing have to be given to the house elf directly? Because in the books Hermione places her hand-made hats around the common room. The house elves of Hogwarts then refused to clean that common room because of the clothes. Does that mean that a house elf just has to pick up an item of clothing?
Does anyone know some Warhammer 40K lore? Am I allowed to make such references here? Yes? No? Anyway. The origin of the Orks is said to be that a very powerful race of great thinkers "created" them (maybe bred them? who knows) as physically strong beings to protect them. Those Orks were much stronger than their creators; however, they were "programmed" not to attack/overthrow them (they might have done so anyway..).
I personally don't understand how house elves became the personal slaves of wizards. I was always wondering that they, unlike goblins, centaurs or other magical creatures, even though they are magically quite powerful, allow themselves to be mis-used so much by wizards.
I think they are magically programmed not to disobey. Dobby does, and he has to punish himself - he doesn't want to punish himself, but he has to. They HAVE to obey, just as they HAVE to be loyal. They have no choice, so it's the same, I think.
And a last thing I want to ask is if it is literately impossible for some magical reason, for them to dis-obey their master, or is it just their strong loyalty?