You may have wondered from time to time if your dog is part kangaroo the way he jumps up and down to greet you or horrified guests. And despite all your efforts to stop the jumping, your dog continues to accost your friends and family at the front door, all the while embarrassing you as you try to explain, "He's just being friendly."
Why do dogs jump all over people in the first place?
In order to understand why dogs jump on people you will need to look at the history of dogs; well not the entire history, but a little snippet of it anyway. It's been widely accepted by the scientific community that dogs descended from wolfs. (How and why the process took place is still up for debate, however)
It's also accepted that domestic dogs are only remotely similar to their ancestors after thousands of years of evolution, but there is agreement that there are a few inherent behaviors that seem to have survived the evolutionary pathway. These behavioral and physical characteristics most likely continue to exist because they serve a useful purpose to our domestic dogs.
Many of these surviving behaviors seem to be used as forms of communication; such as ritual displays to avoid actual fighting. Others include appeasement behaviors that subordinate or young dogs use to "smooth the waters" with their more confident counterparts. The young or subordinate dog may lick the mouth of another dog as a way to avoid conflict, turn belly up, wag his tail much faster, and sometimes for emphasis, urinate. These are the dog's way of saying, "I'm not a threat to you." The roots for a lifetime of jumping on people usually begin with the seeds from some or all of these previously mentioned appeasement behaviors.
Jumping up on people generally start early in life with puppies or young dogs feeling social pressure from humans. The jumping up is the puppy's attempt to reach the mouth of the human to appease what the puppy perceives as bold actions. Of course, most humans wouldn't consider their behaviors "bold," but in the canine world our human mannerisms can send very mixed signals to our dogs. We are, after all, a different species with very different characteristics and forms of communication.
A few of the things humans do to launch future jumping up habits in puppies are; making direct eye contact, bending at the waist and leaning over the puppy, patting the puppy on the head or using a deep or angry voice, as when telling them to stop jumping on people.
What happens next is one of two things: The puppy or dog becomes confused by the mixed messages and tries even harder to appease, or the puppy discovers that he enjoys all of the attention he receives when jumping on people and makes a mental note to use that behavior again.
Dogs repeat behaviors that result in reward or other things they enjoy in life, and in the case of a puppy jumping up on people for attention, it's easy to understand why a he might continue this behavior if everyone is making such a big deal about it!
On the flip side, a dog that learns this behavior during attempts to appease is likely trying like crazy to "tell" his humans that he doesn't want to have a problem with them. His attempt to communicate his submissiveness is via the jumping.
Unfortunately, humans often take stronger actions to stop the jumping; maybe pushing the puppy down, or yelling, "No," and then the puppy tries even harder to appease with additional jumping.
Where are you with your dog?
If you have a dog that continually jumps on people despite your best efforts to stop the behavior, somewhere along the line, your dog believes that is what dogs are supposed to do when people come to your home or when greeting strangers. When a behavior has a strong reinforcement history (in other words, is well trained) you will need an equally strong alternative behavior to tip the scales in your favor. This brings up the question, "What would you like your dog to do instead of jumping on people when they come over?" Picture what the finished behavior will look like so you can break down all the components necessary to train that behavior.
Management and prevention
Once you have decided what you would like your dog to do instead, you will want to prevent him from practicing the unwanted behavior any longer. This is simply managing your dog with things like leashes, crates, baby gates, etc. so he is unable to reach you or your guests. This doesn't change his feelings about the behavior, but it stops him from wearing a deeper groove into that already worn pathway.
Decide and then train it!
The formula for training a new behavior is to prevent the old one as much as possible and make learning the new one as fun and rewarding for your dog.
However, to train a new behavior well, you will first need to assess whether your dog has any training deficits that would need to be addressed before you try to teach the new behavior. If you decided that you would like your dog to sit at the front door, first ask yourself, "Does my dog have a fast sit, the first time I ask?" If not, you would want to train that behavior and generalize it to many areas before adding the distraction of company at the door. This is especially true since dogs (or humans) don't learn well during a crisis or in a high state of arousal.
If you wanted your dog to sit at the door, he should have the behavior of sitting so strong that it has become a default behavior. In other words, he shouldn't even have to think about what he needs to do when he hears you say sit, or give him the hand signal; it's automatic. When you have the filled the training deficits with the foundation behaviors, you are then ready to start working with more distractions and toward the finished behavior.