I've always been obsessed with hats, god knows why but I call them 'tonnies'. So yeah any of you who have watched drugstore cowboy you will know about the whole hat on bed = bad luck thing, well I was watching shadow of a doubt and it said the same thing so I thought I would research this superstition as things like that as I find them fascinating and no word of a lie when I first started dating my boyfriend when ever I was with him I would see a black cat cross the road it was extremely weird and still baffles me.
In the old days people did not wash as much as they do today. Lice in the hair was a huge problem. The lice would go from hair to hat in no time flat. When you put your hat on the bed the lice would jump on to the bed as you will have shaken them loose.
The supernatural brings another explanation. It was believed that evil spirits lived in the hair . You can transfer the evil spirits from hair to hat and then to bed. All kinds of nasty spirits would get you at night!! The myth got magnified if some warm dry night you throw your hat on the bed and there are sparks from static electricity . You could go to hell for less sorcery. It is really really unlucky to throw your hat on the bed for this reason.
Italians and cowboys are apprently where it comes from, and its meant to bring family arguments. But yeah I keep my hats above my bed and they always fall onto it woops, but i've moved them.
Also sorry to bore you more, but when I visited Stockport hat museum I found out the term 'mad as a hatter' was because in the Victorian era (Lewis Carroll)hats were made with lead inside them, so when the hat got hot the lead would infuse into the hat wearers head and make them crazzzzzzzzy.