It sometimes seems as though we live in a selfish world. People allow shop doors to close behind them without looking to see whether there's someone following. They don't make way for others when they're walking along a footpath. They carry on loud conversations on their phones right in your ear. And these are just the minor irritations of everyday life. I'm sure you can think of much worse examples yourself.
So what's the answer? Do you fight fire with fire? Do you become twice as selfish yourself? Well I think (and hope) not. There's a lot of evidence that altruism can play a major role in our overall mental wellbeing. In a neat twist, it turns out that doing good can actually make you feel good. I suspect the reverse is equally true, too: those who behave selfishly end up with lower moods.
I also reckon that just occasionally our good manners rub off on those with lower standards when it comes to being thoughtful. But even if you can't make a dramatic change to the world, you can at least improve your own day by thinking about others. So why not give it a try today?