Astrological Systems

There are many cultures that have their own astrological system. I am curious as to if and how they interrelate in some way which I believe would give a measure of credence to the field as a whole. Or are they similar to religions which seek to interpret based on different beliefs?

Here are some aside from the western zodiac:
Chinese
Vedic
Native American
Mayan
Aztec
Celtic Tree
Runic
Arabic
Ancient Egyptian
Ancient Hebrew
West African

Astrology

No matter what your opinion is on this subject, why is it that to some degree almost everyone has found or could find some truth in their zodiac sign? It seems the signs are distinct enough from each other so that not just anyone could so closely identify with a sign not their own. Also, I believe, noteworthy is that there are so many other cultures throughout history that have developed their own system of astrology. This fact complicates trying to validate one way to interpret over another.

I have long wondered if knowing the characteristics of your 'sign', whatever system, consciously and/or unconsciously changes your perspective of yourself and hence, your actions, on any scale? I have met many people not interested at all in astrology, often not even have read anything about their sign and yet, they still usually 'fit their sign'. I'd be interested to see if any studies have been done on this.

I have been wanting to get to the deeper meaning of this subject, in a serious manner and decided to research 'scientific astrology'...is there REALLY something to this??

Here are some links I found:
hhttp://tinyurl.com/d6fwou
http://tinyurl.com/cky5dh

I will try to keep up with posting my findings ;)