"Your dog is barking because he thinks he's in charge. Your dog is sitting at a higher point on the furniture because he thinks he is higher ranking than you. How to fix it? Make him think you're pack leader by squirting, scruffing, poking, rolling, hanging, popping, zapping, etc."
Beware the trainer who tells you that you have to use aversive tools or methods on your dog because of what he thinks or to change his thoughts. No one can read your dog's mind.
Modern dog trainers don't worry about what the dog is thinking. We focus on observable behavior. In other words, what the dog is DOING.
Barking. Lunging. Digging. Swimming. Growling. Biting. Forging. Lagging. Rolling. Jumping. Cowering.
All of these are behaviors, things you can see. These aren't technical behavioral terms and each has many variations, but they are all behaviors that anyone can look at and say, "When the dog sees another dog, he does 'X'."
From there, we decide whether or not we want to see more of that behavior, or less. If we want more, we devise ways to reward the dog when he or she performs that behavior. If we want less, we develop management plans to minimize the opportunities for the dog to practice that behavior (which also means minimizing opportunities for the unwanted behavior to be inadvertently rewarded), and then we decide what behavior we want the dog to do, instead.
I completely understand the motivation to figure out why our dogs are misbehaving and to know what they are thinking. If we could only understand their reasoning, we could craft a convincing argument that will help them see the error of their ways.
Fortunately, we don't need to read their minds to get better behavior.
Thanks to over a century of research, we can understand how dogs learn (operant and classical conditioning) and use that knowledge to increase or decrease behaviors and to change associations to stimuli that trigger fearful or aggressive responses.
We can learn how street/village dogs (75% of the domestic dog population) around the world behave without human intervention and we can use that knowledge to better understand our dogs' motivations.
We can learn how to recognize the body language that indicates varying levels of stress and we can use that knowledge to determine an underlying cause to a problem behavior and/or predict when our dog's are close to biting or fighting.
We can learn how stress affects behavior and learning and use that knowledge to provide low-stress training environments to ensure our dogs can be successful.
We can learn what factors contribute to fearful and aggressive behaviors and do our best to mitigate or eliminate those factors, when possible.
What we can't do is read minds. Fortunately, getting good behavior is not dependent on supernatural abilities.
Focus on what dogs are doing (behaviors) and not what they are thinking (thoughts).
My dog may think he's the Uber Alpha Mega Pack Leader, or he may not. When we are on walks, he walks at my pace and gives me his full attention when we pass by other walkers. When I call his name, he comes running. When helping me work with a client's reactive dog, he quietly lies on his mat and waits for my instruction. Who knows, maybe he thinks he's totally dominating me with his exceptional manners.
The point is, he has exceptional manners. And he didn't learn them through telepathy (or aversive methods). He learned them because I rewarded observable behaviors that I wanted to see again.
You get what you reward!