I guess I see things a little differently. When it comes to apologies, they mean nothing to me. I never expect anyone to apologise to me and always wonder why when people do. Saying “sorry” doesn’t change a thing. If someone is sorry, I prefer them to show it with their actions going forward. You’re sorry? Great, don’t tell me; show me. If it’s something trivial, like you step on my foot, and I think it’s an accident, I might briefly be annoyed, but I’ll get over it quickly. I’ll be moving on before the ‘s’ has finished sounding. And if I think you did it on purpose, well then I’ll be in your face and we’ll have a problem. Either way, sorry doesn’t come into it.
EDIT: And yet I still find myself apologising to people. Especially strangers. Maybe it’s a British thing, too damned polite.
Flittr 
Or maybe it’s a polite thing, a human thing, a socially acceptable thing
It’s definitely a polite thing, and obviously it’s socially acceptable. Question is, is it really necessary? For me it rarely is, but many are conditioned/trained to apologise for every small thing. Growing up in another culture one might not be that way at all, so it’s not necessarily “a human thing”.
Just my take. Thanks for reading and commenting!
So, on that note, is thanking someone necessary for a small thing?
No it’s not, I just like to give thanks 🙂