My kitty was like that when I first took him home from a shelter.
I'm not exactly sure if there was abuse before, but I was told that someone had abandoned him (and another kitty) boxed up in front of the shelter when he was 4 months old. (I adopted him when he was 5 1/2 months old and now he's 2 1/2 years old)
It took him a long time to realize that my hand is not there to hurt him. At first he either panicked and ran to hide under the bed, or just froze flat on the floor and didn't move an inch.
Almost 8 months after he came home, he started trusting me and now I have his full trust (at least I think I do
) but besides me he's still terrified by human presence.
I'm trying not to assume anything, but for the fact that he's so terrified by human (especially adult men. he's a little better with women, and he's perfectly fine with other cats and dogs. even big dogs...) and that he was abandoned in a box in front of a shelter, some horrible things might have happened to him when he was a baby kitten. I don't know. I try not to think about that.
Right now I'm just hoping that he becomes a bit more social. I don't expect him to go purr on stranger's lap, but at least stop going under the bed every time someone rings the doorbell.
At least go hide when the stranger's actually IN the house, not outside...