I’m sure you never disagreed with your brother, but my bro and I have different views of how tight to hold the steering wheel on washboard & rough roads. I say to hold tight and he says loose.
You are both right.
Loose allows you to better feel road feedback coming through the steering wheel.
Driving on rough roads is called “white knuckle driving” for a reason.
I have never held the steering wheel tight on washboard roads, go with the flow, my thought. Speed is probably a bigger factor, I go at a speed that feels comfortable, hear tell if you go fast enough it smooths out but not a practical thing in my book.
I am of the go fast enough to only hit the tops of the bumps opinion.