Let us assume you are looking at a puppy that is between four and seven weeks of age. At this point, his behavior is a product of genetics and how the breeder has managed his activities and environment. The latter cannot be stressed enough. It forms the process known as 'socialization,' the development of interactive skills with members of its own and other species and learning to be comfortable in different situations and environments. The personality and behavior of a mature dog will be strongly affected by how it interacts with littermates, mother, people, and various external stimuli that it encounters during the first 12 weeks of life. The breeder will control a portion of this period and you the rest.
Relating to mother
From the mother, it receives the first stimulation to breathe, nurse, urinate, and defecate. She also trims the umbilical cord, cleans it several times a day, keeps the puppy warm, and ensures a safe and secure environment. She also provides disciplines when its behavior exceeds limits that only she understands. She supplies everything needed.
Relating to littermates 
From his littermates, the puppy acquires additional knowledge on how to interact with members of his own species. Through their play, puppies learn about dominance and submission, get an introduction into mating behavior, and receive a wide range of stimulation for the development of their senses and physical abilities. Puppies that have no littermates or come from litters that were split up at too early of an age, typically have difficulty interacting with dogs later in life. Not knowing how to react when confronted by a member of their own species, they tend to be either overly shy or aggressive. Often, they fail miserably in multi-dog households.
Relating to people
At the Breeder: Through handling and play with humans during their first seven weeks of age (which all good breeders encourage,) the puppy learns to trust and interact with people. Without this involvement in their lives they tend to have difficulty forming relationships with or being comfortable around people. Dogs isolated from humans at an early age tend to become one-person dogs. They usually do not blend well into homes that contain multiple children or several adults. Obviously, these traits can be occasionally overcome, but it is not always easy.
In most situations, breeders provide what the puppies need for correct socialization with little effort expended. They keep the puppies until they are seven weeks of age before allowing them to go to their new homes. The mother is left with the puppies throughout most of this period. After four or five weeks, she will be allowed to spend time away from the pups, but she will still be with them for several visits each day. Good breeders love children if for no other reason than to have them around to play with their developing puppies.
In our own experiences of raising litters, we have our children start holding and petting the puppies when they are only a few days old. At three to four weeks of age, we let them play together in outdoor situations for an hour or more on a daily basis. And lastly, most breeders try to expose their pups to many different stimulating environments or situations. They should not be confined to a whelping box or pen until they depart for their new home. They need to learn to respond to many different situations to develop confidence in themselves. Their curiosity needs to be stimulated. If you ever decide to breed your own litter, all these same things will become your responsibility.
Relating to You and Others: We talked about how the breeder must provide the puppy with an environment that prepares it for life among humans, occasional encounters with other animals, and to be comfortable in a wide range of situations and environments. It is referred to as socialization. When the puppy is now in her final home, this process must continue as she is still developing behavioral patterns. In fact, these first few weeks in your home are some of the most important in the socialization process.
We recommend keeping the puppy’s schedule full for the first few days in your home in an effort to limit any loss it might feel from being separated from its littermates and mother. However, between seven and ten weeks of age there is an additional problem. At this time, most puppies go through a period in which they lose some of their self-confidence. Trust comes harder for them and things that we would expect them to be comfortable with suddenly elicit anxiety or fear. Where before they would boldly charge into a new situation, they now seem apprehensive. This could be anything from loud noises, new people, play that is a little too rough, going to a new place, etc.
Behaviorists have found that this has little to do with the change in where they are living or the separation from their siblings or mother. Even in cases in which the litter remains together, this same behavioral pattern is noted at this age. Do not overreact. Your puppy will mature through this and be just fine if you do your part. You do not want to become overly protective and isolate it from the outside world. We think it is better that during this two to three week period, you increase the range of its experiences by small steps, not giant leaps and bounds. Choose activities that can be controlled. Introduce the puppy to new people including children, but do not let thirty kids come screaming at her from all directions. Let her meet the neighbor’s dog, just not the rowdy one down the street. At approximate 12 weeks of age, this period comes to an end and most owners will see their puppies become bolder toward new people, animals, and experiences.
Continued socialization through the first year of life
From this point through at least one year of age, it is imperative that you make every effort to expand the puppy’s environment and expose her to new things. During this stage of their lives, puppies should be around as many different people and animals as possible. Take them with you when you go for a walk, shopping, or even to work. Encourage your children to bring their friends over to meet their new pet. Take an obedience or training course where they will meet other dogs. All of this is important.
Dogs that are isolated during their first year of life develop many problems. A few will become aggressive, but the majority are more likely to become overly shy or timid. They lack confidence in the presence of new people or situations. They cower in the presence of strangers. They jerk at their leash to get away from children or other pets. Forced to be in a new place, they may sit shaking behind you, drooling, and panting rapidly. In the worst case scenario, they may become fear biters. This is a behavioral pattern in which dogs, when encountering new people or pets they are afraid of, do not know how to react and simply attempt to bite the stranger. Once this develops, it can be very difficult to overcome.
The bottom line is: involve the puppy as much as you can in your daily activities. She will be well-socialized and happy. Besides, that is the reason you got her, right?
