The Odd Disorder Anarchic Hand Syndrome, or "Dr. Strangelove Syndrome"

If you've seen the movie Dr. Strangelove, you'll remember the odd character whose right hand seems to have a mind of its own, sometimes erupting into a Nazi salute, other times choking the neck of its owner.

There really is such a disorder (though not as dramatic) known as anarchic hand syndrome, or "Dr. Strangelove syndrome." The disorder is often described as hands "arguing" with each other, or with the person, making it seem as if the person has two different wills competing with each other.

The BBC has a good article for the general reader; if you're more scientifically inclined, you can also read articles from professional publications here and here.