Better riding: The white knuckle problem

As we have discussed before, the thumb rule for good riding is to think of the upper body as a mechanism of control over the motorcycle. The lower body has the considerably more physical task of holding on to the motorcycle. So how hard do you think you should be holding the handlebar?

The correct answer is just firmly enough so your hands cannot be thrown off by an unexpected bump. But no harder. The more nuanced answer is that you should be able to maintain this light but firm grip at all speeds. Obviously, this is harder than it...