It’s essentially for selfish reasons, but that doesn’t mean we aren’t putting ourselves second or even third. You won’t be doing stuff your brain doesn’t tell you to do and your motivator is called dopamine. Where that comes from is irrelevant. But when you have a good heart you will tend to want to make the world a better place. And you will live knowing that you did. However, it is possible to have a bad day and still have the enforced neural pathways that got trained because the dopamine has made your brains remember the last time you did that. At the moment you might not even like doing it but you do it anyway. Because it’s “the right thing to do” or so your brain says. When you have felt a hardship you may also feel compassion with someone and do not want them to feel what you felt. But the essential reason is the same.

So it’s absolutely possible to be selfless, just not for selfless reasons. Doesn’t mean we’re all selfish assholes. On the contrary. We get happy in groups, so we want the groups to be happy. We do everything for that. If we don’t then we tend to not really be there anymore. And we’re not required to, but we do. That’s the selfless part.