A:Puppyhood can be divided roughly in three stages: the first one that affects the life of a puppy at its new home is the maximum socialization period, between 7 and 12 weeks. During this most important “window” in the puppy’s mental development, it must be introduced to every possible aspect of normal everyday life. Anything left out during this period will be a cause of inhibition in the adult dog, and a puppy not fully socialized between 7 to 12 weeks of age will never reach its full potential as an adult.That's one of the reasons that puppies should go to their new homes not earlier than 8 weeks of age.