By 7-8 weeks puppies have fully functioning brains (as shown by EEGs) and are capable of learning anyting, keeping in account their short attention spans, of course. More importantly, learning at this age is permanent. Many behaviorists agree that this is the best time for the puppy to go to its new home, unless the breeder is equipped with the time and help to treat each puppy as an individual-including crate training, housebreaking, seperation from its mother and littermates for extended periods of time and extensive socializtion...... Other behaviorists/breeders believe that 7 weeks is too early for placement in new homes. SInce fear in puppies is increasing rapidly during the 7th week and puppies are fearful of strangers and new situations, seperation from the dam and littermates mayb e traumatic at this time. Scott and Fuller reserarch also showed that the dog-on-dog (primary) socialization isn't complete at 7-8 weeks and if placed in a new home without continuing and correct exposure to dogs the puppy will not learn to coexist in a dog world or when meeting new dogs.