The concept of “critical periods” in the emotional development of the dog is a well documented one. Dogs that are denied human contact until they are over 12 weeks of age seldom make good companions. Somewhere in that time span is the “critical period” during which dogs can be socialized to another species, us. Research into critical periods in the development of the dog’s mind has been carried out since the early 1960’s. In 1961, the magazine Science published the results of the most elaborate and definitive experiment that had been carried out to that date, a report that concluded that socialization in dogs, the ability to learn to live compatibly with dogs and with us ends at 12 weeks of age and that the most critical period was 6 to 8 weeks of age.
Later on, in 1967, Science published again on the subject. The magazine reported Scott and Fuller’s work which showed that pups raised in completed isolation to 7 weeks of age could still recover completely and become socially normal. They also reported that outside contacts as infrequent as twice a week and for only twenty minutes each time were enough to ensure normal development as long as these outside contacts occurred in the critical period between 4 and 12 weeks.
Out of this and other research came the concept of the first critical period, this lasts from birth to 12 weeks of age, in the development of the dog’s mind. It was divided up this way:
1. Neonatal period: 0 to 2 weeks
2. Transitional period: 2 to 4 weeks
3. Socialization period :- to dogs 4 to 6 weeks
– to humans 4 to 12 weeks
Neonatal period: The pup is almost wholly under the care of the mother and the way she behaves with her pups will influence their behavior in later life. Remember, these first weeks of the pup’s life are its most important, that the earliest experiences it has will have a tremendous impact on the mind of the pup. There are no apparent maternal behavior centres in the brain and it seems that both genes and learning are involved. There are, however, variations in the quality of mothering and these will affect the behavior of her pups. Because the pup’s brain is still in such a formative state, the experiences it undergoes now will have a tremendous impact on the development of his or her mind. This is why the first 12 weeks of age are such a “critical period” in the pup’s life. Early handling – stressing – at this age is actually good for the emotional development of the dog and probably makes him better able to cope with stressors later on in life. Mild stresses early in life influence the adrenal-pituitary system, fine tuning it to respond in a sensitive and graded manner later on in life rather than in an all or nothing fashion. The question remains as to exactly what is the optimum amount of stress that a young pup should receive because it is also known that too much stress at an early age leads to subsequent retarded development. Mild stresses will accelerate body growth, reduce emotionality and possibly increase resistance to certain diseases.
Transitional period: This is when most of the pup’s sensory abilities come on stream. The pup’s world opens up and suddenly his littermates and the rest of his environment have a dramatic effect on his developing mind. First comes vision than hearing and balance and finally touch and pain. The transition period from 2 to 4 weeks of age is the beginning of the most important period in the young dog’s life. For the first time his senses are being stimulated and he will be forever influenced by the images that now form in his mind. How a dog behaves at any time in his life is a result to a constant and fluid interplay between his genetic potential and his environment. It is during the transition stage that many of the building blocks of the dog’s future behavior are laid down. What he experiences now will affect him for the rest of his life. No one knows exactly how it happens but as the pup leaves the transition period; he enters what will be the most important 8 weeks of his life, the time during which he learns to live with both his own kind and with us.
Socialization period: Any type of social relationship that a pup eventually develops begins as a problem and ends as a habit. These relationships are always adaptable and it is during the next 2 months that they are most malleable. During this time the severity that the mother uses in altering her relationship with her pups has a direct bearing on how the pups will ultimately behave with people. How a pup treats and is treated by his littermates during the next few weeks of his life is just as important for us too. During this time play becomes a big factor in the development of the dogs mind. Playful activity has a number of functions socially speaking there are three: play stimulates communal behavior; play affects and moulds adult social behavior; and play predicts the future dominance relationship within the pack. Play develops the pup’s mind because it leads him into different situations where he has to innovate a solution. During the socialization period, play is carried out for more than its own sake. It is a source of skill, information about littermates and it deflects natural aggression. It can also be used to advance the social status of a pup. Dogs that are isolated form other dogs during this period in their lives are often hyper aggressive towards other dogs. They haven’t learned how to inhibit this behavior. Pups that are denied play activity up to 12 weeks of age can develop bizarre behaviors including self-mutilation in order to reduce tension. They are poorer learners, have a greater fear of people, animals and noises, and are shyer and more antisocial. They will avoid stimuli and are reluctant to explore. In short they are canine misfits. Between 3 and 8 weeks of age, pups should be exposed to potentially fearful stimuli in the environment, kids, aerosol sprays, vacuum cleaners, vets, postmen, cats, street noises, and this sensitization should continue throughout the socialization period up to 12 weeks of and on into the juvenile period. Remember, this is the most sensitive period of a pup’s life. Dogs that don’t meet people until after the socialization period are antisocial, difficult to train and dingo like in their fight, flight and freeze behavior. Dogs that don’t meet other dogs during the socialization period are fearful, make poor mothers and are inhibited or over reactive when they meet other dogs.
From a veterinary viewpoint, a major conflict arises from this information for, as all dog owners know, standard medical advice dictates that pups should not meet other pups until at least 2 weeks after the final puppy vaccination which is given at 12 weeks of age. Some vaccine manufactures suggest as late as 20 weeks of age to finalize the parvovirus inoculation. But what happens to the pup’s developing mind if he is isolated for so long? The answer to this conundrum depends on what role you want your dog to play in your life. For dogs that will be forever human oriented, this medical advice can be safely followed. The consequence will be a human oriented and human attached dog, one that should be responsive to command and readily obedient to you but possible fearful or aggressive with other dogs. If you want your pet to be a dog oriented dog however, the standard medical advice is dangerous to follow.
The degree or intensity of play at this stage is also a portent of the future. Pups that are too playful aggressive during the socialization stage make difficult pets in the future. If there is any one rule to follow at this stage of a pup’s life, it is a simple one. Never, ever play fight, especially during the socialization period, with potentially aggressive and dominant dogs. Do not role on the ground and simulate fighting and do not play tug in an aggressive means. If you do you will be creating dramatic problems for the future.