This is a chart showing milestones in a kitten’s development before and after birth over the first weeks. It is based on John Bradshaw’s Cat Sense: The Feline Enigma Revealed. If you click on it you go to my Flickr photostream where you can use it, if you want to, by grabbing Flickr’s code to embed it in webpages etc..
Bradshaw states that the personalities of cats are strongly affected by what happens to them when they’re tiny kittens. I suppose we know that because it is the same for us when we are babies. Kittens who undergo prolonged stress during their first few weeks of life may end up with personality problems. He also says that they may have cognitive problems. I presume this means learning difficulties. This hints at the different intelligence levels of individual cats being affected by the environment.
A kitten can become excessively attention seeking towards his or her first owner if he is abandoned by his mother and then hand reared by the person. Some may grow out of this attention seeking behavior.
The best cat pets come from kittens who had a relaxed mother and were well fed by her. They grow up in a stable world, one in which they are able to hone their social skills. Conversely, kittens raised by a mother who struggles leads to an uncertain world in which the kittens have to survive with more difficulty. Consequently, there is more stress and more competition. The kitten may develop into a cat that is less successful as a pet. This seems to mirror human development as well.
I think Bradshaw is referring to the two general personality types of cats, namely, the more confident and outgoing cat versus the more timid, nervous and cautious cat. In general, people prefer their pet to be the former.