You list several examples where people are selfish. In many cases, the selfishness is not inherent in people, it is a combination of the setup of the system and social norms.
Using your "boarding a plane" example. Compare boarding a Ryan Air flight from Frankfurt/Hahn to a Lufthansa flight from Frankfurt am Main. Specifically these two, because Germany still has a somewhat cohesive culture/cultural identity, and one which values taking care of the community over self (for example, at dinner, you ALWAYS pour water/wine for others before you fill your own glass).
Ryan air. No reserved seats. Pushing, shoving, anger, aggression-- really ugly selfish behavior.
Lufthansa. Reserved seats and gate crew controlling boarding. Orderly lines, no stress, people smile and let the families with children go ahead. I won't call it selfless altrusism, but it is a big step up.
Swedish airports (Arlanda/Stockholm at least) paint a big yellow line about 1 meter back from the baggage belt, and people stand behind the line. Not everyone, but when someone breaks this rule they get socially disapproving looks from the others.
There are two nash equilibriums. When the majority of society shows respect for others, you have a really pleasant society where showing respect/care matters. Freeloaders need to be strongly discouraged, because in the short term freeloading is "optimal". You'll get your bag faster, you'll get the seat you want on the Ryan Air flight.
There is a tipping point when too many people start to freeload, happens at around 5-8%, and the system slips into the other nash equilibrium where everyone selfishly tries to grab for themself. Makes for a hellish society.
The tragedy is that it is very hard to move from the selfish society to the caring society.