in korea it’s actually very important who’s born earlier! bc you have to call them either oppa (female to older male), hyung (male to older male), unni (female to older female), or noona (male to older female). i always forget that some other cultures don’t do this, also i think it would just be weird to ask who’s older if it weren’t needed. usually ppl in korea can figure out who’s older by listening to who calls the other one of the names above, although some twins don’t do it