Answered: What is this movie??

Hello everyone,
I'm new here, and on a desperate search to figure out the name of a movie. My father-in-law saw it on tv back in the 70's or so, and doesn't remember the name of the movie or any of the actors. He has been trying to figure this out for over 20 years now, and any help you can give us would be so appreciated!

Here is the general plot of the movie..
It was a movie about a teacher who moved to a community where strange things were going on. Everything was very secretive, and the children all shuffled their feet when they walked. Eventually, the teacher was alone with some of her students and asked them about the strange occurances in the community and why they all shuffled their feet. They then confided in her that they could all fly.
The teacher then confronted the "Elders" of this community about this information, and asked them what was going on. They told her about how they were part of some old, advanced civilization and were trying to protect themselves.

This is about all he remembers. I can't seem to find any info on it, and although a few people remember the movie - they don't remember the name.
Anyone have any ideas?

Thanks so much,
Lee