Interesting. I often feel safer in smaller (but not too small planes), where I don't see the wings visibly flapping. Something like a A320 or a 737.

With 747s the wings flap up and down quite visibly in turbulence, and you can even see the fuselage twisting if the curtains aren't closed between the sections.

There's also just the wall thickness to mass ratio. You ever notice that you can crash toy RC cars all you want and they never break, but if you crash a real car even mildly it's rather easily totaled?