It all depends on the socialization of the children. If the kids are very socialized and interact with older kids a lot (even older siblings) they tend to grow up faster and stop believing in Santa around age 5-6. I was the oldest child in my family and my mum and dad were quite creative (and good liars). I believed in Santa right up until I was about 8 or 9. I believed in the easter bunny until I was about 10.
well i stopped at like 9 cause i saw my mom put all the presents out and fill the stockings..... so that depends if u go creeping at night or just be nice.
It usually depends on when they figure out that Santa isn't the one giving the gifts. For me, I think it was at the age of 5ish.
I have a friend who believed in the easter bunny until she was 14!
Omg haha that's quite old!