Mental Ability

This can be contrasted with Mechanical ability. This contrast developed in the 19th Century, with its abundance of machines. But developed further in the 20th Century, with the addition of Radio and Photography.

The result were people far different than they had been a few centuries earlier, Mental skills were now required, and many people did not have these.

Some people had the ability to control other people (such as Hitler) and they went far.

The 21st Century saw the addition of the Computer that required exotic skills never seen before. The gap between the skilled and the non-skilled made communication difficult.

This made most people demand a return to a simpler life that they could understand and control. They elected simpler (but dictatorial) people to high places.

This was not very smart.