I think it is a combination of both genetic and environment. Sometimes it really is partially determined by the mother cat and how she treats her kittens. They get imprinted pretty quickly. Yet we have had cats we loved equally and maybe one in the litter was just plain shy, or just plain mean, or just plain sweet as can be. They do interact to each other and also our moods though.

Trey, who is our cranky old, 12 year old girl picks on the other cats when her routine is rudely interrupted in any way whereas the other two just flow with changes in routine.

LB who was a stray woods wise kitten we took in at age about 7 mos. you think would be wild, but he is very affectionate and loves to cuddle and do the PC with me. He still gets his daily woods time, but not at night ever.

Gusty, our Maine Coon beauty, was originally a show cat and breeder (now retired at 3 from both) Got her last year from a breeder. She spooks whenever we have company, but is a real lap cat with us. She has never been outdoors. I have noticed a big change in her disposition and trust level since we got her. I think it is due to all the love and affection and attention we have given her. She is less shy for sure - and more affectionate. She had to survive in a crowd of several Maine Coons(some of them large so developed clever coping skills), but now is very laid back and seems to know that she doesn't have to be clever here with us. She holds her own in a brilliant manner. She has never been in a cat fight that I know of.

Sometimes it takes a lot of time and patience, but they can change - just like people. Maybe not a lot, but at least a little.

I spent 34 years in Alaska. Treybabe