Japan -- A Funny Little Hypothesis

My understanding is that most Japanese do not believe in Western astrology and, yet, it's a common topic of discussion. They routinely tell people what their Sun sign is in casual conversation.

I think most likely what is going on there is that they don't find it threatening because they don't take it seriously, so it's a good topic for making small talk, and it also solves a somewhat unique social challenge for them.

In Japanese language and culture, my understanding is you address people using honorifics on a routine basis and there is a long list of honorifics to choose from. Which one is correct depends in part on which of you is older.

All well, fine and good except that it's rude to ask someone their age or birth date. So how does one determine who is older and who is younger?

Sometimes this is obvious. A child addressing a grown-up, for example. Anyone can tell at a glance who is older and who is younger.

But what if you are all school children in the same grade (presumably all born within the same one year period)? Now how do you know who is a few weeks or months older than you or younger than you?

Well, if you casually tell everyone your Sun sign and if everyone else tells you theirs, anyone who does not share your Sun sign can be pegged as older or younger than you based on their Sun sign because it tells you which 30-day period they were born in. If there are 36 students and their birthdays are distributed evenly across the signs such that there are three kids each per Sun sign, this little chit chat session has solved it for you for all but TWO of your classmates.

And I think that is probably why it's a popular topic of discussion in Japan.