There are some behaviors that dogs inherit from their wild relatives. Inherited behaviors are strongly influenced by breed; for example, a border collie tends to have strong herding instincts while a greyhound (and other sighthounds) will have a strong desire to chase moving objects.
Some dogs have an innate calm; others are innately nervous. My Lally seems to be the nervous type — sudden noises and movements will startle her. Human behavior around animals can help tone down or key up these behaviors.
Inherited behaviors can’t be unlearned but you can work around them. When Lally gets excited, she tends to box — jump up and paw at me. Which makes sense, considering she is half boxer. I can’t make her not want to express her excitement, but I can encourage her to express it in other ways. When she gets ready to box me, I tell her to go get her ball instead. Lally gets to release her energy and I get to save myself from boxing.
Dogs learn through association. An action that is rewarded (with pats or treats or praise) will be repeated. An action that comes with a negative reward (yelling or other punishment) is less likely to be repeated.
Dogs don’t reason. This is why you can’t punish a dog hours later for something he did. He won’t make the connection between the chewed slipper and his action and your anger. If you can’t catch him in the act and stop him while he is chewing, you are wasting your time with any punishments.
Young dogs — between the ages of five and twelve weeks — are the most sensitive to learning. This is the best time to socialize your dog and start basic obedience training. Dogs can and do continue to learn throughout their lives, but it can take more time and patience on the human’s part. Behaviors are embedded in older dogs and may be harder to relearn. Don’t give up! Expect some relapses as your older dog tests your willingness to let him have his own way.