However, when we are standing or sitting in a chair and they come bounding over to greet us, jumping up on us and trying to reach our face, we must not bend over and exchange hugs and kisses. If we do we are training and rewarding the puppy for jumping up. Eventually, most of us decide we no longer like our puppy jumping up to say hello - usually when the puppy gets bigger and more rambunctious. What used to be cute is now obnoxious and even dangerous if the puppy is jumping up on children or the elderly.
Other commands can be substituted for ‘sit’ if you prefer, such as ‘stay’ or ‘down.’ However, if your dog simply gets too excited to execute these commands properly (as is often the case, especially with puppies) try diverting their attention elsewhere. Ask them to go find their ball, or a favorite toy, as a way to distract them and expend some energy. And, as always, reward the good behavior with praise.
Our inconsistency perpetuates the problem. Some of the time we tolerate the jumping and ignore it. Other times we reward the behavior by exchanging enthusiastic greetings. But when we're dressed up and the puppy's paws are muddy, it's a different story. Reprimanding the puppy for jumping up usually does not work. Either the puppy misunderstands the reprimand as praise or he gets even more excited and the jumping gets worse. If the reprimand is severe enough, the puppy may stop jumping at that moment but it doesn't solve the problem altogether; and it certainly is not a very nice thing to do. It's very similar to a person approaching you with a big smile, arm extended to exchange a hand-shake and you bopping the person in the nose. Even if your puppy learns that jumping up on you is not a good idea, he will usually get away with jumping up on everyone else.
Also, it's your job to never let anyone else allow your puppy to jump up on them! They will say, "It's OK, she's just a puppy, I don't mind if she jumps on me". You must rush in and pull the puppy down immediately, put your pup in a sit, praise the puppy then scold the person ! Continue to hold the puppy in a sit and let the person greet the pup. Explain to them they can never allow the puppy to jump on them - the puppy must sit to be greeted. To stop the jumping up behavior in pups, I do as much people training as puppy training!
Why do dogs jump up? A plausible explanation arises from their ways of communicating with each other. A puppy greeting an adult dog often licks the adult’s muzzle -- a polite, deferential behavior. Dogs, of course, descend from wolves, among whom muzzle-licking is how pups get the grownups to regurgitate food for them. Domestic dogs rarely nourish puppies this way, but muzzle-licking has survived, maybe because deferential behaviors are handy for a social animal. Think of humans saying “No, after you.” Muzzle-licking is also an appeasement behavior -- something you trot out to de-escalate a fight. A human might lift up his hands, palms toward the person he’s arguing with.