Imagine you are taking a young child to a haunted house. You know that nothing bad is really going to happen, people in masks and makeup are going to jump out at you and try and scare you, and you know it is all just in good fun. However, to the child, it wasn't so much fun. They are terrified, screaming, and trying to get away. Most normal parents look at that child and realize they aren't having a good time, this is too scary for them and you either need to come back by yourself at a later time or help your child realize it's not so scary. You don't spank the child, scream at them, or jerk them around to make them get through it because you want to. You do the reasonable thing to help the child work through it so they aren't traumatized by the experience. Unfortunately, people don 't show the same courtesy to our canine friends. We expect them to stay in the dog park because we want them to. People expect them to enjoy being in a public space with other dogs and people because people want it and they better act like the ideal dog we all strive to have. Even more unfortunate, people try to make them behave no matter how they are feeling no matter the consequences.
Behavior issues in dogs are widely misunderstood. People focus just on the surface of what they are seeing and not understanding what is actually happening. Yes, the dog is growling and lunging on the leash. That is the behavior that people see. What they don't see is the "why". Why is the dog growling and lunging? Is the dog aggressive? Is the dog scared? Is it an over-arousal response? People don't understand the why, so they act on the outward behavior they see: the growling and lunging. Because of this, people punish the behaviors they are seeing. They make one big mistake, however. You can't punish an emotion. Many people that don't have a thorough understanding of animal behavior, body language or basic learning theory make this same mistake, which can be detrimental to the overall problem. Here are some of the basics. Emotions are how something makes you feel. Behavior is what you literally do. Behavior acts on your emotion. Punishment is something that happens that is more likely to decrease a behavior occurring again. Reinforcement is something that happens that is more likely to increase a behavior occurring again. Punishment and reinforcements have no impact on changing emotion, just behavior that occurs as a result of that emotion. In summary, you cannot punish emotion.
This is a very important concept to understand because many people try to affect behavior change in their dogs, without really working on the main crux: the emotion behind it. What happens is people see their dogs growling at other people, get embarrassed that their dog is "aggressive" and punish the growl, maybe with a pop of the collar, yelling "no", maybe even a shock collar. If it is effective enough to make the dog not want to experience that again, the growling may stop. But it doesn't fix the true problem. The dog is growling because it is scared of other people. The emotion occurring is fear. The dog growling is a way they are trying to express that fear and ideally, make the scary thing go away. So if you punish the growling, do you really think you are making the dog no longer scared of people? Definitely not. All you are doing is suppressing the behavior you didn't like. At the same time, you are conditioning the dog to create either good or bad associations with whatever it is they are scared of. If you punish the dog for showing it is scared, you aren't going to create a good association with that thing the dog deems scary. You are feeding into what the dog already thinks, which is that particular stimuli, whether it be a person, dog, car, etc, is not a good thing, definitely scary and not something to be trusted. You may be able to stop the behavior you didn't like, but you didn't change the emotion behind it. Then that emotion manifests itself in other ways with different behaviors. Maybe the dog growls more quietly, maybe now it just barks or whines, maybe it finally goes in for a real bite when it can't handle the fear anymore. Maybe a whole different behavior issue occurs as a result of this. The dog demonstrates stress in everyday situations now and anxiety that to an average person isn't worth taking notice, but to a trained professional are very obvious. The problem is still there, but people end up under the false pretense that the problem is "cured".
Similarly, you cannot reward emotion, but you can create associations that can change or impact an emotion. When dealing with fear or anxiety, you can either change it or make it worse. When the dog looks at the scary thing and lets out a low growl or tries to back away, if you immediately give a high value treat, you are not rewarding the growl. You are attempting to condition the dog to think that when this scary thing is present, good things happen. In essence, you are attempting to change the emotional response of fear to one of joy. Similarly to a scared child, you don't just get angry and punish them when they are terrified; you do what you need to do to make the child more comfortable and ideally enjoy the experience. When the dog performs a behavior in order to earn a valuable reward, the emotion associated with that reward is joy.
So what happens when you give a dog a high value treat when they growl or bark at something the dog deems scary. The dog starts to associate this scary thing with food. Over time, with many repetitions and a methodical way of working with the dog in a positive way, the dog no longer feels fear towards this scary thing, but feels joy and excitement when they see this once scary thing because it means food is coming. Usually, the growling or barking goes away. Sometimes it may persist, but the experience is different. I actually had this occur just the other day. The dog barked on the leash at an oncoming person, which in the past wouldn't have been unusual, but instead of the low, scary, distance-increasing bark the dog emitted, it was a high-pitched, excited, and happy bark that came out. Then the dog immediately looked to the owner for treats. Everything about the dog's body language showed content and eagerness to earn food. There wasn't a stitch of fear, stress, or uneasiness like the dog had presented before. The counter-conditioning done in the past changed the behavior associated with that stimuli from that of fear to that of joy. Now, here's the tricky part that actually isn't that complicated: you may be wondering what the whole point of this is if the behavior didn't even go away. The difference is that the emotion is in a good place now where the dog is content and happy and displaying a behavior out of excitement as opposed to fear and stress. So now, you can punish the behavior and still have an appropriate emotional response in addition. Now, you wouldn't feed the dog any high value treats unless the dog was behaving quietly and appropriately. Then the dog will earn high value treats for appropriate behavior, while still maintaining a good emotional response. Not rewarding when the dog barks, etc, so long as the body language shows the dog is happy or content, will cause the behavior to go away. The dog will still maintain those positive emotions to that stimuli. This is the beauty of counter-conditioning. You are changing the way the dog perceives something so you can change the behavior without creating other unintended side effects.
So if you have a dog like this, what should you do? First and foremost, consult a qualified professional to help you with this issue, ideally someone CPDT-KA, CPDT-KSA, or CBCC certified or a certified veterinary behaviorist. A trainer that utilizes choke collars, prong collars, or shock collars is not qualified to help in this sort of issue because they don't have a deep understanding of basic learning theory or classical conditioning. If someone recommends a mainly punishment-based approach such as startling the dog, clapping, etc, they also are not qualified because they are focusing on the behavior, not the emotion. Also beware of trainers that preach "balanced" training. This usually means they utilize many punishment based techniques and will use rewards for other things, but most likely they will not be focusing on the emotion, but just the behavior presented. Behavior issues can be very complex and require the proper guidance to work through them. Don't delay and seek out the help of a qualified professional. The wrong advice or wrong utilization of certain techniques can make the problem much worse down the road or make it much more difficult to work through. As I always tell my students, "emotion trumps behavior. Focus on why the dog is doing what it is doing so you can change the behavior afterwards". Control the emotion, you can easily control the behavior. If you only focus on behavior, it is a battle you will keep playing with since the emotion has never been changed.