We should not try to compare the yelling and berating of "students" by military drill instructors, or their equivalents, to techniques better used by instructors in other environments. Military basic training instructors have a unique responsibility and initial objective. Their primary start point is to break down the individual's sense of self and selfishness, and replace those sentiments with selflessness, being a reliable team member, and immediate compliance with lawful orders. In today's "me" environment, this is no small or easy task. As this needed indoctrination progresses, and the the individual becomes part of a cohesive, co-reliant team, yelling and berating generally becomes less frequent, as peer pressure comes to the forefront. From my perspective of being a former military instructor in a variety of aircraft (a post-initial military training environment), yelling is only necessary and effective to immediately stop or start an action for safety or tactical reasons.
