Its very different. A passenger has a stake in the safety of the vehicle and reacts to surroundings. They pause when the driver is entering a complicated intersection and sometimes remind the driver to look at the road.
Not in my experience. They're playing with the music, on their phone, reading, hanging their feet out the window, etc. In fact if you're one of those backseat drivers "reminding me to look at the road" (as if I'm not paying attention) you can find your own transportation.
