I've been reading the Mrs. Pollifax mystery thrillers. They are about an old widower who's bored with her garden club so she volunteers at the CIA to be a spy. Quietly amusing.
Anyways in the latest....
1. In Anatolia its the custom to move the village when the well runs dry. In America, we had boom towns or gold rush towns and now we have ghost towns. In my 'end of the Bronze Age' scenario as global warming kicked in, we would have had a lot of abandoned cities. And currently, we do have a lot of cities that are sitting in the middle of a dessert, or are underwater.
Just a thought for society design.
2. As A1 pointed out with his 'point the finger' (which Yoda did with a stick), you might have physical effects that increase psi power. In the MP mystery, the queen of the gypsies is a clairvoyant who's strength tripled when she lost her ability to walk, and now has to get around when she does with crutches. Also, its more common (and I've discussed this before) to have the idea of losing one's vision is neccessary or helpful in psi powers.
I could argue this with the 'Einstein Syndrome' by Thomas Sowell. Einstein has an area of the brain that is analytical that is double the size or something like that of a normal person. At the same time, he could be remarkably absent minded and forgetful.
Neuroplasticity is the ability of the brain to use different parts for other uses. Forex, you catch a bullet and it destroys the part of your brain that controls your right arm. You might be ablee to retrain the brain in other areas to do the work of the original area.
And if someone were to no longer need the part of the brain to say control legs or use sight, why that part could be retasked to esper powers.
When I first saw this, I was expecting a similar concept to Mrs. Pickerel. She was a storybook heroine who was just a normal, retired old lady, who, through incredibly strange acts of happenstance, found herself in the most unusual of circumstances. Landed on the moon in one book, and found herself at the helm of a nuclear submarine in another. All through sheer happenstance. (She might as well be a verser, ya know?) Pretty cool book series.