"Litters of puppies were isolated, with the bitch, in fenced acre fields from 2 to 14 weeks of age. They were removed indoors at different ages, played with for a week, and returned to the field. The pups manifested an increasing tendency to withdraw from human beings after 5 weeks of age and unless socialization occurred before 14 weeks of age, withdrawal reactions from humans became so intense that normal relationships could not thereafter be established."
----- Freedman, D.G., King, J.A., Elliot, O. 1961. "Critical periods in the social development of the dog" Science 133, 1016-1017.
Previous blogs have touched on genetic factors that influence the physical and behavioral characteristics of dogs. DNA is what it is as soon as the genes from the mother and father are recombined result in a zygote. After this, there is no way to intervene in the the genetic code itself to achieve the behavioral or physical outcomes we want for our dogs.
Despite this, we're far from powerless. The genetic code itself sets up a period in the dog's life where "nurture" (learning, experiences, external influences like diet, etc.), not "nature" (genetic factors), determines the ultimate outcome. Dogs are an altricial species, meaning they are born lacking many of the basic faculties for survival. Puppies are born blind and deaf. They cannot urinate or defecate on their own; even their GI tract is formed sterile and requires seeding with appropriate bacteria from the environment. Unlike precocial species, such as cows whose calves keep up with the herd in a matter of hours after birth, puppies are helpless. As counter-intuitive as it may seem, this is canine evolutionary survival strategy, and it has been very successful.
From the time puppies are born - and especially after their eyes and ears open - until at least 12-16 weeks, they enter what is known as a "sensitive" (or "critical") socialization period. For the first five weeks of life, or up until about 3 weeks after their eyes and ears open, the puppies do not even have fully developed fear responses. They interact completely uninhibited with the environment, wholly dependent on mom at this time and held back only by their inability to see, walk, or defend themselves well. This means that by default they remain in a safe place of their mother's selection, soaking up information about everything they encounter and categorizing it as normal and safe. After five weeks, they become increasingly sensitive to stimuli and can make enduring negative or positive associations. As they get even older and are able to venture further afield without mom, they are increasingly hardwired to be suspicious of anything novel they encounter. In wolves, this sensitive period is extremely short, but it has been lengthened in the dog through domestication (although there is significant variation across breeds and individuals within breeds).
Breeders and owners can and must take advantage of this critical period to influence what their puppy will be hardwired to consider "normal" and "safe" as an adult dog. Especially before they're prone to fearful responses, exposure alone (obviously within reason) can often be used to teach a dog much of the human world is normal and safe. After that, we can deliberately curate experiences to be positive exposures by pairing new stimuli with those that stimulate positive reactions in the brain, such as food and play. Anything that is neglected during this period will be categorized by the brain as novel, and therefore potentially dangerous. This is simply how animals are hardwired - humans included. While we can try to impact early on whether an adult dog turns out more or less optimistic when encountering novelty, we never again have the leverage we had in the earlier parts of the critical period to cement in the brain that novel stimuli are normal and safe.
Below we review some of what we introduce to puppies given our responsibility and unique opportunity as breeders to do so during the earliest portions of the critical period. As the puppy gets older, owners and trainers can of course work on classical conditioning and desensitization exercises to do some remedial socialization (defined as "positive exposure"), but the likelihood of success and the number of repetitions it takes increases exponentially with the passage of days (let alone months or years). Thankfully, an excellent foundation early in life can create relatively optimistic dogs, who maintain a sneaking suspicion that novelty may represent an opportunity for exploration and fun.
The common bite triggers - Veterinary behaviorist Dr. Ian Dunbar has identified common bite triggers for dogs that breeders and owners should deliberately create positive exposures for as early and often as possible. Among these are, unfortunately for us, hugs. Dogs are not primates; they are not hardwired to interpret a hug as an expression of affection, but rather only as a manner of restraint. The good news is, we can accustom dogs to tolerate and maybe even enjoy mild forms of restraint by pairing restraint with food, play, or other primary reinforcers. After hugs, touching of the paws, collar, ears, testes, and tail must be deliberately, positively desensitized.
Environmental triggers or changes - As trainers, we've addressed a variety of concerns with adult dogs, and so have a laundry list of things to which puppies must be deliberately socialized to avoid problems later. Compared to humans, dogs are not generalizers - for example, they do not assume from one interaction with flooring in the home that all substrates are safe. While it's bizarre from the human perspective, dogs not exposed to shiny marble, tile floors, carpet, wood floors, and etc., are likely to balk at them as an adult upon their first encounter (to the point that service dogs fail their qualifying exams for this reason!). For city dogs - or dogs that we expect to tolerate the city well even on occasion - subways, trains, skateboards, bicycles, joggers, backfiring engines, garbage trucks, ambulances, police sirens, etc. all need to be deliberately socialized.
Social Triggers - Puppies also need to be positively exposed to a variety of people - children in particular. (Statistics show that the most common bite is between a kid and a dog they know, e.g. their own or their neighbor's). Golf bags and luggage, puffy winter coats, umbrellas and hoods, wheelchairs and variations of gait due to crutches or injuries that cause a limp, etc., are all potential triggers. Really, anything that alters the natural silhouette of a human figure can be suspect to a dog (especially one with impaired or degenerating eyesight). When it comes to dogs, it is unsurprising then that puppies also need to meet a variety of friendly, well-socialized dogs, including dogs with pointy ears, hanging ears, cropped ears, docked tails, fluffy coats, huge body sizes, small sizes, etc.
Lifestyle Prep - If your dog will be a hunter, he or she will benefit from specific socialization, such as crate or confinement training, positive exposure to loud noises - particularly gunfire, and other features of hunting and training including leashes, whistles, other dogs, hunting gear, and of course hunters themselves. The dog of a fisherman should probably get comfortable on some boat rides early on rather than push a boulder uphill trying to adapt the dog later in life.
It is important to err on quality over quantity (although that's no excuse to not get in sufficient quantity). The malleability of the brain at this age is a double-edged sword: while it allows a dog to make an enduring, potentially life-long association that something is not a threat during the sensitive period, that same biological pre-disposition also easily allows the puppy to find negative experiences particularly salient. They can create enduring negative associations that manifest in fearful behaviors such as hiding, growling, snarling, biting, etc. - potentially for life.
Ca' Rigada takes advantage of the Puppy Culture method of rearing puppies, which emphasizes creating optimistic puppies with pro-social communication skills and the foundations to live a life of behavioral wellness. This includes preventative measures against the most common behavioral issues for which owners contact trainers or surrender dogs, particularly house-training, fear, separation anxiety, confinement anxiety, and lacking or mal-adaptive social skills.