it is me, or is your post a little demeaning and self important? i mean, technically, you're 'yelling' at me when using CAPS.
but, you're 'yelling' not out of anger (i would hope) but rather to bring attention to your point since you seem to think/feel that my perspective of the usefulness of yelling as a teaching tool--in the right contexts--is dangerous or harmful.
so in this way, yelling needn't be about anger or trying to demean anyone, but instead be a method of drawing stark and quick attention to something that is potentially harmful, to demonstrate how potentially harmful it is, and the level of care necessary to prevent harm.
granted, speaking low, cold, and quietly is equally effective--and the same basic underlying technique (using volume and tonal quality to bring attention to something dangerous).
so, apparently it is useful tool for trying to gain someone's attention when you disagree with them and find their behavior or opinion DANGEROUS!
there's a big difference between yelling at someone for missing a math problem and yelling at someone who could have harmed, maimed, or killed someone due to their inattention (negligence).
it might also be noted that educational study and theory is narrow in it's study. most educational theory is centered around teaching subjects that are not life/death situations and/or teaching subjects in the classroom setting where there are not life/death situations present. There is very little study about the 'practicum' process--in which there is real-life, on the job training and what that training entails and which tools are most effective in preventing harm to another.
it is common, in these fields where life/harm/death situations are prevalent, for students to be starkly and quickly admonished for doing something that would harm another, for the purpose of increasing their awareness--and taking that theory from the classroom and using it in a practical way.
and it should also be noted that teachers who teach in a life/harm/death practicum situation know that yelling is only one of many techniques, that different students need to be treated differently, and that yelling should only be used as a means of drawing attention--not demeaning or acting in anger--toward the student.
it is true that demeaning a person is problematic. it is not true that yelling is per se demeaning.