I had 4 cats at one point, 2 came from a good home, one from a shelter where she was born to a sick mother and another with a very sad life story, apparently, someone adopted her or something and probably because she had some virus that made her shit like crazy, put her in a closed shoe box and threw the box into the trash so that the cat would die inside.
She was rescued by a friend who couldn't keep her cause she already had 2 dogs, it took -3 month to get over the virus and have the cat restored to health. She had a very strange personality, maybe due to her traumatic childhood and maybe not, but she was an affectionate fun cat who loved playing and enjoyed people and weren't at all afraid of them, as she did in the beginning.
Judging from my 4 cats, their personalities are effected by their first experience, but they can overcome a lot, and usually if treated lovingly and responsibly, they react in the same way.