A metaphor that helps me think and talk about such phenomena.

Every group of people doing a dance is generating a force field with which the individual dancers align themselves. For example, if a line of belt-hold dancers is sweeping forward, any single one failing to actively do so will feel the force acting toward alignment with the whole (as a double yank on your chain!). It's a lot easier and more pleasant to bounce as your line-dance neighbor bounces than to move against him — the dance force field is pressuring you to line up with it. Of course, if your two neighbors are doing different things, you don't experience much of a force — the field strength is low in your part of the line. You've probably noticed how field strength tends to drop as you move from the head of the line toward the tail.

The natural, easy, traditional way of acquiring a dance is as a single learner in the smooth strong field generated by a group who all know it well. No matter where he is getting his input from, the learner gets firm, consistent modeling and cues. If there are variations, at least each is likely an appropriate variation — not a deviation. If the learner gets negative feedback on what he is doing, it is probably because that behavior is wrong. The learner is likely to get negative feedback if he needs it, because errors are conspicuous in a group with high degree of concensus. Dances that achieve this sort of currency with enough members of a community are that group's folk dances. They belong to the community, persist even with changes in membership, and so become "traditional." Nobody bothers to ask the novice about preferred learning style — you get with it or you don't. On the other hand, if at first the learner does not succeed, he can try, try again — the dance is not going away soon. One can test the degree to which a dance is such a collective possession by trying to change the way it is done and observing how hard it fights back against your individual efforts to deform it — this is measuring the strength of the force field the group generates for that dance!

The artificial and difficult way of introducing a dance is as a solo teacher in a group to which it is totally new. The instructor is challenged to singlehandedly generate the field, persuade the group to line up with it, and ultimately to spontaneously regenerate it without the teacher. Meeting this challenge may involve heavy investment in tools, techniques, skills, aids, personal charisma, and other such complicated auxiliary stuff. Success may depend on sensitivity to individual learning styles, stubbornness, and luck. At first the learner's only dependable model is the instructor. His neighbors in the line may or may not be giving the right cues — and an amazing amount of information goes sideways along the line, for better or worse. There is no assurance that doing it right will be reinforced by resonance with one's neighbors. And the new dance is at great risk, since it must be accepted by enough members of the community to propagate itself although it has limited opportunities to impress itself on them.

After I ponder strategies for replacing the Hardest Way by the Easiest Way of teaching, I offer a pair of applications of the theory that work along the spectrum between these extremes:

1. The Cadre Approach. Introduce a new dance by teaching it to a select few victims first, minimizing the adverse leverage of the one-to-many problem. Then use this core group to instruct others the Easy Way — but only as many as can be effectively aligned by the field generated by the initial Cadre. Repeat as needed to establish the dance. If a small group has learned the dance together somewhere in the outlands, the Cadre comes ready-made.
2. Divide and Conquer. In a teaching session, place experienced, autonomous dancers between pairs of novices to get good cues to the latter from their neighbors in line. We systematically use this approach when teaching newcomers to our performing group, and I use it occasionally in recreational teaching as well (when it can be done diplomatically).

The sobering truth that the teacher, in a one-to-many situation, must work hard and smart and probably use auxiliary aids (such as the general-purpose mind which is standard onboard equipment for most humans) that understandably may drive a reality-weary teacher to drink.