No, I'm not imagining people pushing others hard. Everyone has a choice: 1. passively propagate forward whatever force is being applied to them from behind 2.

No, I'm not imagining people pushing others hard. Everyone has a choice: 1. passively propagate forward whatever force is being applied to them from behind 2. actively resist by applying some amount of counterforce (this doesn't mean the person in front of them experiences 0 force, but only that the force they experience is less) 3. actively add one's own force in addition to whatever force they are experiencing from behind I'm positing that (3) is selfish even at low forces, even if you're near the back of the line, and your scenario of 1k people doing (3) with an individual contribution of 1lb of force describes 1k wrecklessly selfish people. The moral I'm proposing--and it's a really fucking easy one--is don't fucking push people, even gently.