I'll give my opinion here on breeds, genetics, temperaments, personality and how we as people play a role in this.
Instinct is just that, instinct. It tells your dog they need water, food and shelter to survive. We provide these basics to our dogs. The water being from our tap, food coming out of the fridge/freezer/food bag/etc, shelter being our home, their crate, a dog house. I have one the prefers the underside of the deck, but thst's not important. Instinct tells a dog to look out for itself first, then it pack. Dog will defend itself in may ways, out thinking it's opponent, biting, being vocal, or running, Fight or flight instinct. We all have it. Dogs being a pack animal will defend it's pack. The pack will varie as to your household, my pack is my 7 dogs, 1 cat, my husband and myself. Pack instinct comes into play as to who eats first, who goes through doorways, who controls the house. I would hope that most people here control their household as the dog is not the one out working to sustain the "pack". These are basic instinct.
There really isn't "instinct" within breeds. There are bred for qualities being temperament, stucture and movement. Lets just go back to when dogs were not breeds, just random canides. Most likely a person had a dog as a companion, took the dog for a walk and it ran after a rabbit and killed it. Man sees that the dog has a use. This use is cultivated by breeding more dogs like this first rabbit hunting dog. By selective breeding, you eliminate the dogs that don't have the desire to run after the rabbit, from your breeding program. After a few generations of only breeding the dogs that want to run after rabbits and kill them, you have a Rabbit Hunting Dog. Makes life easier for man. Man finds livestock and is able to use the livestock for food, shelter or clothing. But it's hard to move so many animals at once from one grazing area to another. His rabbit hunting dog starts chasing the livestock around. He finds that the dog can move the livestock. So Man starts breeding his dogs to chase the livestock, but not kill it. Now we have herding dogs.
You see, all these "habits" are created by man, from observing behavior of the dog. Dogs can be trained to do anything. I have trained Borzois to be water retrievers. Not an easy feat, but was successful. Shelties are typically a "barky" breed. You can train them to be quiet, but they really want to bark. You can change a dog's habits through breeding selectively for certain traits. The way to do it is with heavy culling of the animals that do not "fit the mold".
Personality is entirely environmental. I find that if you take a dog of a certain breed, lets say a Saluki who is by nature independent, aloof, not a Lab personality and throw it into a household with Labs, you will change the personality of the dog. The dog will take on the habits, traits and personality of the dogs around it, being the Labs. That is why I usually have a few different breeds at my house. The Shelties have taught the Borzois to be barkers (Borzois on a whole do not bark). The Whippets have taught the Shelties to run across the back of the couch and perch on furniture. The Shelties have taught the Shepherd/Newfie mix to not eat the cat (I think he was eating cats before I got him, long term stray behavior). The Shelties have taught the other dogs to crowd around you when you come into a room (herding behavior). Not fun with a 120 pound dog pressing against you. The Shelties taught the Dobe puppy how to play nice. Dobes usually play rather rough and a lot of face and air nipping. The Borzois are the confident ones, the Bichons hang out with them more.
I just put my first Borzoi down on Tuesday. I picked her up at 9 months old. She lived wth her breeder who had Borzois, Scottish Deerhounds, a Whippet, and a Norwich Terrier. Goody had not beed socialized all that much, other then going to shows. At the time I was a 4-H member. She went everywhere with me, club events, petting zoos, nursing home visits, malls, you name it, she went there. At the time we had two older shelties. Goody was socialized with a lot of dogs of different breeds and temperaments. She was a Golden Retriever trapped in a Borzoi body. Minus the retrieving habits. She loved everyone and all dogs. On the other hand, her siblings were not social with other dogs. Two were know to attack other dogs at shows, ring side. Unfortuanatly, these two were bred. I never bred Goody as I'm not sure how much of the unwanted behavior would come through. I knew I could socialize them to be pleasant dogs, but who knows how much work someone else is going to do. She was a happy dog that lived in the house with a family. Her siblings were kenneled most of the time. Personailty is developed by your lifestyle and attitude. If you don't feel comfortable taking your dog to the vet or the groomer, your dog is not going to feel comfortable there either. Pack instinct coming through.
Well, I wrote too much. But they are things that are on my mind when I was reading this posting.
Kari