QSA and other's I strongly believe cats are just like humans, you get your shy ones, your extroverts, your grumpy ones, your happy ones, your skittish ones, and your gentle ones.

My own two are like chalk and cheese, different in every single way, one is gentle, sweet natured and skittish or timid, and the other is grumpy, not too fond of human touch, but he has a purrsonality all of his own, that I love about him, he is my lovely boy all the same.

Both kitties were strays, one picked up from a shelter the other roaming my street, so I have really no idea about their parent kitties or their life before here., either could have been abused and both were neglected, who is to say how that affected one or both.

I would imagine kittens born to feral mother's and father's would be less sociable all the same.

They are a mixed bag as humans, and each one has their own endearing qualities, and of course that particular vet service should be ignored.