Jumping is rewarded with attention. When Jackson leaps up on his people, , they react in one of two ways. Either they try to calm him by petting and stroking him; or they jump back, trying to push him off while waving their arms frantically and making lots of noise. To Jackson, both reactions are direct rewards for his leaps and bounds.
When the dog jumps up, you need to withdraw of all your attention. Quickly turn away, fold your arms, make no eye contact, and say nothing. After a short while – although puzzled by your lack of attention – he’ll stop his frenetic behaviour. Once the dog has settled, give him lots of attention and serious petting.
Once the dog learns that that are no rewards for jumping, the behaviour should decrease. As the dog is calming down, give the sit command and reward the dog for the good sit. This is especially helpful on walks when the dog meets a favourite human. Just before he gets excited, give the sit command, then reward him with food, petting, praise, etc. Get the human to come down to the dog’s level and greet the dog that way.
Oh, and one more thing. When your visitors say they don’t mind if your dog jumps on them – ignore them. Stick to your training and don’t make exceptions. The trick is to make sure that all family members, as well as guests and friends, know how to react in this situation: by correcting bad behaviour, and rewarding good behaviour.