There is no empirical evidence or even theoretical or dialectical reasoning showing that astrological signs affect human behaviors or relationships in any way.
Quite the opposite, there's empirical evidence showing there is absolutely no correlation between astrological sign and personality, here's an example:
I can't believe I'm even going into this.
There IS theoretical reasoning that astrology affects personality.
That everything in the Universe has a gravitational pull, and where you are and when you are born the Universe was in a certain configuration, and the different gravitational pulls have an effect on your make-up.
Now one might say that it would make more sense for that gravitational pull to affect ones physical characteristics, rather than personality which are a mixture of Nature and Nurture. But then we can just look at phrenology, which shows links between personality and physical characteristics (including morphology of the skull).
Obviously just a theory, but I think it's viable.
Not that I follow Astrology like a religion, but I think that it is true about people, I've seen that.
And I think it's possible that people can be attracted to all different signs, but that doesn't mean that they are compatible with all signs. How many times have you initially been attracted to someone and then turned out to not like their personality so much, or perhaps it just didn't work with your own? That's happened to me in relationship for sure.
I think that in order for people to see how astrology works you have to go far more in depth than just your sun sign- people assume that astrology says that there are only 12 different kids of people, but there are so many other factors affected by so many different heavenly bodies. Every person with a Cancer sun sign is NOT exactly the same- and astrology does not ever claim that. Just as every single INFJ or ENTP or ISTP or ESFJ are the same- that's only part of who we are.