Two parts to this:
- Do passengers tend to behave in ideal ways?
- How do the cabin crew behave?
We know what's supposed to happen: the passengers are supposed to follow instructions, leave possessions behind not inflate their life-jackets inside the aircraft, and so on.
To what extent does this actually happen?
I know for example that passengers have inflated their life-jackets inside the aircraft (with tragic results, in the case of Ethiopian Airlines 961, where some passengers became trapped inside and drowned as a result). I can bet that some passengers will inevitably want to insist on gathering some tremendously important belongings.
I assume also for example that the management of the emergency exits isn't simply left in the hands of the passengers sitting next to them, but that the crew as far as possible take charge, and that generally they become ferociously assertive and intolerant of any nonsense from recalcitrant passengers.