In Dog training this question is bandied about on a regular basis. "Dogs need a 'Pack Leader', they need to know who is boss.' I agree, to an extent, although I don't use those terms simply because they leave a bad taste in my mouth and have different meanings to different people. But take the word 'Leader' out of that context and it is a very innocuous, sometimes even highly regarded word.
Let's look at it first in our human relationships. Remember back to your high school or college days. Were your favorite teachers the ones that made learning a chore, boring, monotonous and sometimes even punishment based, drudgery? Did those teachers garner your respect by making you fear punishment for talking or misspelling a word? Did you want to work harder for those teachers or just do the bare minimum so you were not punished or humiliated? Did you respect them? By respect I mean not only acting respectful by not talking back or speaking out of turn but did you feel they were someone you could look up to, someone to be revered?
Perhaps you were in the military where respect and loyalty are paramount to your survival. Did you develop true, meaningful respect for the leaders that were relentlessly abusive to you or the people you served with? How much loyalty would that type of person garner? How hard would you push yourself for the type of person that never made you feel that they had your back or were supporting your growth and learning?
What about friendships? What kind of friend is someone that is unpredictable in their behavior, abusive in their language and makes you feel worried every time you are with them? How close would you let them get to you, how hard would you work at that relationship?
Employers that undermine your work or threaten you with long hours, pay cuts or disciplinary action to serve their own purposes, how hard would you work for someone like that? Sure you may work long hours to try to remove the threat of job loss, but will you be happy doing it? Will you enjoy going to work every day or will you be fantasizing about tropical beaches and perhaps the prospect of your employer getting fired!
Now put these scenarios into play in your relationship with your dog. Knowing that dogs have a limited ability to understand our language, lack of reasoning capabilities and cognitive abilities equivalent to a 3 or 4 year old child, would it be effective to train your dog using fear as a motivator? Fear is indeed a motivator, we wear seat belts for fear of injuries in an accident, we wear helmets, bullet proof vests, ear plugs, etc. for any number of activities that carry the fear of pain or injury. These things keep us safe, but they don't teach us HOW to be safe. Driving instructors teach us how to drive safely, gun safety courses teach us how to handle weapons; it's the teachers that are important.
For long term effectiveness and success with your dog (and human relationships!), be a leader that makes learning a game, gives respect to your dog, understands how they communicate and leaves fear in the dark. Teach using love, kindness, compassion, clear rules and support and you will have a dog that WANTS to work for you, that finds you the most amazing thing in his life and sees the world in a much better, less scary way.
Be that kind of leader, those are the best!