Dogs are not born friendly to humans. No, that’s not a misprint. Dogs are born to
become friendly towards people, but this happens only if they meet friendly people
while they are still tiny puppies. Scientists have known this for half a century, but the
implications are still not universally applied or even widely appreciated. Today, many
puppies are still raised for the pet market under impoverished conditions, conditions that
predispose them to a life blighted by fear and anxiety, and causing behaviour that will
not endear them to their owners or indeed anyone else they come across. Yet all this is
entirely preventable.
Domestication has not adapted dogs to human environments; it has merely given them the
means to adapt. Exposure to both people and man-made environments must occur, in a gentle
and gradual way, to enable them to learn how to cope. This process starts in about the
fourth week of their life and goes on for several months. If the exposure is either
deficient or defective, the dog will develop deep-seated fears or anxieties that can be
very difficult to eradicate later. Although some details of precisely how this happens
have not yet been scientifically explored, the overall process of this ‘socialization’ is
well charted, and it is a tragedy that so many puppies do not receive enough experience of
everyday life to allow them to cope adequately with their life among humans.
In 1961, a short paper appeared in Science that completely revolutionized our
thinking about the bond between man and dog. In order to study when puppies are most
sensitive to exposure to people, the researchers raised five litters of cocker spaniels
and three litters of beagles in fields surrounded by a high fence, so that they never saw
people – food and water were provided through holes in the fence. Then every other week
from the time the puppies were two weeks old until they were two months old, a few of them
were taken out to live indoors for a week’s ‘holiday’, receiving an hour and a half of
intensive contact with people each day. At the end of their week’s socialization, they
were put back in their field with their mother and littermates.
The timing of the ‘holiday’ was absolutely crucial to how the puppies reacted to being
handled. At two weeks old, they were too immature and sleepy to interact much, but the
puppies taken out at three weeks were instantly attracted to the person looking after
them. They would paw and mouth the researcher and play with the hem of his lab coat. Five-
week-old puppies were wary for a few minutes, but soon started boisterously playing with
the person. Seven-week-old puppies needed two days of coaxing before they could be
persuaded to play, and nine week-old puppies took even longer, only becoming friendly in
the second half of their week’s holiday.
The timing of their first introduction to human contact was absolutely crucial to how
the puppies reacted to people later on. All the puppies in the experiment were taken out
of the field when they were fourteen weeks old, and at that point began to live with
people like normal dogs. The five puppies that had spent all of their lives in the field
ever learned to trust people, even after months of intensive handling. The six that had
been taken on ‘holiday’ when they were only two weeks old, and were then returned to the
field for eleven weeks, fared better: though they were initially quite wary of people,
they became somewhat friendly after a couple more weeks of gentle attention. All the other
puppies were instantly friendly – remarkable, given that some had last seen a human over
half their lifetime ago. The six that had not seen a person for ten weeks were initially
difficult to leash-train, but training the others was straightforward.
Overall, the results indicated that puppies need some (but not very much) contact with
people if they are to react in a friendly way towards them. There also seems to be an
optimum age for this contact to be effective. Two weeks old appears to be too early.
Twelve weeks old is definitely too late; by this age the puppies observed in the study had
become fearful of anything they had never been exposed to when they were younger. This
implies a window of opportunity between about three weeks and ten or eleven weeks of age –
what the scientists referred to as their ‘critical period’.