One day when my friend was messing around he stabbed his chopsticks into his food so they stuck upwards and outwards. His mother actually scolded him, and demanded he removed the chopsticks immediately and to never do that again. His mom said that, aside from it being extremely rude, in Japanese culture it is considered bad luck. My friend has never done something like this again after being scolded by his mom.
He learned about this superstition from his mother when he was having dinner with her one evening. He was just messing around at the end of their meal, and was shocked at how angry she suddenly became when he did this. The fact that it upset her so much is truly what made this superstition stick with him, even though he does not actually believe in the superstition.
Superstitions like these are shared among many different cultures. My friend is actually Chinese, but his mother referred to this as a Japanese superstition. This goes to show that they can be shared among many different cultures, and do not have to be specific to one, although they can vary within cultures when they are shared. I am sure the Japanese superstition translates a bit differently to the Chinese one or to the American one, and so on.
I’ve also heard about this superstition before, and I think it may even have been from my own mom who is also Chinese. I find this interesting, but I also do not actually believe that it will bring you bad luck. I still would not do this though, because I am worried it will come off as rude and impolite.