I suspect that when we have our next big earthquake here in the USA, probably on the west coast somewhere, we will see basically the same pattern we have seen in the past. There will be some looting ( in some cases, survival scrounging) and there will be a lot of constructive ad hoc community action, which may not get as much attention as the more negative actions during the event.

With a well developed infrastructure, we can likely return things to normal fairly quickly without long term disruption. I seriously doubt we will ever approach the Japanese standard of behavior, turning in large quantities of loose cash found after the event, and other selfless acts.