Thoughts on astrology and star sign attraction

I am pretty sure that this never happens. Even with humans - when you meet someone for the first time, you won't know their birthday.

 

It's a self-fulfilling prophecy.

There's a psychological phenomenon where telling people something about themselves, whether true or not, even once permanently changes their personality a tiny bit. If you want someone to be nicer to other people you don't tell them "you're mean and should be nicer" you tell them they're a really nice person. The more they're told how nice they are, the more nice they actually become due to their mind trying to adjust itself to other people's expectations without them even realizing it.

When people are told what their star signs are, once they know what theirs is supposed to mean, every time someone comments on them being that sign they'll move more and more towards acting like that sign is supposed to.