Socialization Basics
It seems that more and more dog owners are hearing about the importance of socializing dogs when they're young, but until every single one hears the message, we need to keep hammering it home. There is also a ton of new research coming out all the time both about its value and about when and how to do it, so even if you're an experienced dog person, you might be surprised by some of the new guidelines we're hearing from behavioral experts.
For the purpose of this discussion, I'm defining socialization as the process of exposing a puppy to positive experiences with all kinds of different people, dogs, and situations during the crucial developmental periods of preadolescence (8-16 weeks of age). Dog trainers and behaviorists recommend it because extensive research and experience have taught us that during a crucial period when puppies are young, they tend to be more accepting of new sounds, sights, smells, and people. During this period, they are also more impressionable than older dogs, so the lessons learned stick very deeply.
Obviously, older dogs can still learn to accept new and potentially scary things, but the process typically takes longer and can be more difficult, so part of laying the foundations of a lifelong relationship with a well-balanced dog is giving a puppy lots of positive, mellow experiences with the kinds of things he'll need to be comfortable with throughout his life.
That means puppies need to meet people of all kinds of shapes, sizes, dress codes, faces, voices, and behaviors. An unsocialized adult dog might be fine with his family, but outside that zone of safety, he's more likely to be fearful or overexcited around unfamiliar things like glasses, hats, or beards if he's never learned that they aren't signs of danger. New stimuli can be very intimidating to dogs, and if they react with fear, that can lead to more than just an unhappy experience. Fear and other kinds of overstimulation can cause issues ranging from common problems like an inability to focus around distractions all the way to very dangerous behaviors, like running off or even fear biting.
Any unfamiliar aspect of a situation can mean that the dog does not know what to do to create safety for himself. In the house, with people he knows, he has learned what he can do to feel safe, like where he can go to hide or what behaviors he can offer that get him positive attention, food, toys, and games.
But when the situation changes, even in ways that might seem small to us, the dog might not even know that the world is still safe and that humans are still going to be kind and predictable. Dogs are masterful at a lot of things, but they are not good at generalizing or inferring. As humans, we are so good at those things that we naturally take them for granted. For example, if your dog has never met a man with a beard, that man might seem like a brand new creature. It's like if you turned a corner and were confronted by a bear wearing a tuxedo.
So your dog might react to create space and safety for themself, trying to back up, showing appeasing body language, or barking to say “back off.”
That doesn't mean you can just throw a pupapy into any old situation and expect him to be cool with it. The flip side of the socialization period is that it's also a period in which traumatic experiences will stick deep, so don’t create a situation in which your pup is freaking out and you force him to keep confronting something he's afraid of. While you should be working hard to socialize your pup, you should be working equally hard to make sure that each experience is mellow and rewarding, and you never want to teach him that he can't escape a scary situation. If your pup shows signs of stress with what you're working on, respect that, even if the anxiety is totally illogical. Respect that fear, tone down the experience, and dial up the rewards.
So, for example, when a puppy sees his first adult in a ball cap, he should get a yummy treat, especially if it seemed to make him nervous. If he tries to get away from a new thing, like a trash can, even if his fear is completely unfounded, let him. Teach him that if he's upset, he'll be able to get away and then inspect the thing at his own pace, not that you'll drag him closer or force him into things. Teach him that any bravery he shows will be rewarded with calm praise and a treat or toy.
By sixteen weeks of age, a puppy should have done as much of the following as possible: met a hundred different calm, friendly people; played with a dozen different friendly, healthy, vaccinated dogs; walked on a dozen different kinds of surfaces; seen some of the local wildlife; and had a whole variety of other experiences you can come up with that mimic the kinds of things he'll run into in the life you're planning for him.
Here's a printable checklist in PDF format that you can use to track your progress and make sure you haven't missed any of the common items people overlook when socializing their puppies. The checklist offers overall goals, like meeting 100 friendly strangers and walking on 15 different surfaces, and it also gives lots of specific items and a way to keep a record of how well the experience went so you know what kinds of things you may want to revisit. If it’s not going well, end the interaction and plan to try again later with a toned down version (for example, if a cyclist freaked him out, plan to visit a spot where you can look at cyclists from a greater distance so you can have a good experience together).
One last thing: if you're reading this and your dog is older than sixteen weeks, that doesn't mean that the work of socialization is done. Maybe you didn't do everything the experts recommend before sixteen weeks, or maybe you have an adult dog with an unknown history. It doesn't matter now; socialization is a lifelong process. The early puppy window is really helpful, but every positive experience your dog has with a new thing is still socializing that dog to be more confident and stable. And if you socialized your pup by the book through week sixteen, then pat yourself on the back, but still remember that your work isn't over. You can still socialize a dog after he grows up, and early socialization isn't the only thing a dog needs. If you want a calm, confident companion dog, that's something you create opportunities to encourage wherever you can through their whole life.
Sources: the St. Hubert's Animal Welfare Center puppy packet, the Paws N' Effect puppy packet and class curriculum, the AVSAB position statement on socialization, the ASPCA’s Tips for Socializing a Puppy, Dr. Sophia Yin's Checklist for Socialization, "Human directed aggression in domestic dogs" by Casey et al., Puppy's First Steps by Dodman et al.