Hanka, thanks for the link, it's a very interesting description!!
Andre, Rona was right, I meant the early socialization which pupies receive in the kennel from their breeders who want to ensure they have good start. But I fully agree with you and this is how we socialized K-Lee.
Apart from what Hanka writes, I expose my pups various noises, which I arrange. They also encounter objects of various shapes and surfaces of various texture in they pen. Some are wamer, some colder, some nicer and some a bit less.
I also try to make them familiar with an animal that has a different smell
I belive the early imprint of various stimuli will make them more open to new situations.