Ultimately, yes we are all looking out for ourselves. But there are varying degrees of how much this affects our daily decisions. Ever have someone pull right out in front of you on the road, making you slam on your brakes to make room for them, when they could have waited 5 more seconds for you to pass by before they pulled out? Or how about the mom who gets in line at the store while sending her 4 kids out still shopping, only to make everyone in line wait for them when they get to cashier and the kids are still gone. Or the guy who buys scratch-off tickets, scratches them, and proceeds to turn them in, all in one transaction at the counter while other customers have to stand and wait the whole time? How about the guy who rides mile after mile in the passing lane, doing the exact same speed as the car next to him, not speeding up or slowing down for the 3 seconds it would take to let that long line of cars behind him pass.
These are basic daily decisions people make that affect how outward thinking they are. These days it almost seems like people arent even being selfish on purpose, they simply dont know any other way to be.