Was skimming a thread about learning Japanese for a trip to hombu when I found this gem from Walter Martindale:
More recently, the lectures we had in "how people learn" during PE undergrad studies showed that people pay more attention to demonstration by "significant peer" than by "instructor" or "expert performer" I think the contrast is "instructor" is an expert, perhaps, but he's been doing this for a really long time and I find this difficult... An "expert performer" - well, they're making it look so easy - I'll never be that good. (Neither of these interpretations include the number of years that the instructor or EP spent learning the movement.) However, a "significant peer" who's usually a person of similar age who may have only recently learned the movement gets the reaction "Hey, he (or she) can do it, I bet I can do that too - let's see, the left hand was here, the... right foot did this, the body was positioned here" but all in non-verbal internal dialogue where the person is imagining his/her body doing the movement...
Maybe this is why it is not so great for a dojo to be topheavy? Even if new folk come in, they may not learn as effectively, not seeing any peers having similar success and similar struggles. The gap between what they see and what they can do is too big. There is nobody to identify with, no immediately accessible, intermediate role models. And so they don't stick. And I'm thinking this applies to a whole bunch of other dojo social issues, too. Women and training, GLBT training....