I'm going to visit association again; in dogs it is an important factor. What happens in a moment can have huge implications by the surrounding environment at that very moment. So what is association exactly? The wind blows and a door slams; a dog learns that wind very likely means doors will slam. A dog lunges to see another dog while wearing a pinch collar; they receive pain around their neck and associate this pain to a dog approaching.
Dogs associate much more than we humans do; it can actually take us alongtime to associate things. But for dogs it can happen in an instant and be ingrained forever. Sometimes if you get to work on the misassociation immediately; you can undo any wrong doings. But not always, sometimes somethng that happens remains and no matter what you try to do to fix it; there is no fixing.
Puppies go through a fear period around the age of approximately 4 months; it is important at this stage that you try your best to make it a good one. Many dogs are left with fallout behaviors due to a negative association. Once you learn and understand about association in dogs it is much easier to "get" what is going on with your dog. Maybe your dog is displaying some weird new behavior; suddenly they are acting fearful when they come into the kitchen. This is new; what the heck is wrong with your dog? They never use to act slung down, tail tucked and ears plastered back in the kitchen.
If you look at this behavior and think; sometimes you need to think for a long while, you might remember the day when you dropped a pan right as your dog was walking into the kitchen. It scared the life out of your dog and she ran for cover. So now what you have is a fallout behavior, a result of an association. My boy Luke has associated fear of wind; he had an experience of being waken from a deep sleep from a door slamming which resulted in a seizure. So when the wind blows moving the doors around he is in a fearful state. I can slams doors to a certain degree but if the wind is blowing he is on full alert.
It is all action/reaction for dogs so what and when we do has alot to do with how and what our dogs will learn. Leash aggression is a huge association factor. We see another dog coming our way so immediately reign our dogs in; this behavior alone starts the "hey what's up" reaction from our dogs. What we should do is show them that other dogs walking by results in treats and a very happy or level and calm guardian.
Some association instances cannot be helped; accidents happen even when we do our utmost to avoid them. But your reaction can have a huge impact on that association and if you are quick enough, you can indeed change an association before it is ingrained.