Have you ever wondered what your compatibility was with others based on their sign? You might be thinking of Astrology, but that's actually called Synastry.
In Synastry, they determine love factors like romance, passion, affection, attraction using Mars and Venus based on where the planets appear in the sky. I wonder why they don't teach astrology in school (anymore). Without tools like Wikipedia and Google, you wouldn't know about the ancient civilizations that studied the stars at night. They determined that a year is the Earth's rotation around the star and then broke that down to 12+ months, each based on a Moon's lunar cycle (~28 days - also a female's cycle). Later on, they came up with 4 seasons in a year (solstice/equinox), and 4 weeks to a month (or moon phases) thus creating a 7-day cycle. "...and on the 7th day, he rested". Even today's holiday [Easter] is astronomical, determined by the moon and the equinox.
Astrology is frowned upon in public schools because there is a lack of scientific proof. I agree, you cannot narrow down every particular person's traits based on thousands of years of research, but truths must have a theory before it can be proven.
The signs were originally a universal system describing the different parts of the human anatomy, what a better system than to use apparent "star formations" as symbols, just search "zodiac man". The stars themselves did not have the influence over the parts of the man, they were merely symbols used in a system of understanding. These 12 divisions of "the sky" all correlate to systems in "universally" misunderstood books such as the bible, where we see 12 apostles, 12 tribes of Israel, and so forth. We can see also in various Greek texts as we see in the 12 labors of Hercules and the 12 Olympians. These also correlate to anatomy, where in the skull there are quite specific 12 cranial nerve pairs. The wise individuals who created these systems knew that the brain works by association and by symbols. These particular symbols represented different "vibrational stages" of natural function, but misunderstood by "modern" esoteric minds, eventually faded into obscurity. "Modern Science" also misunderstands alchemy which is actually a similar system, all dealing with symbolically concealed mental processes. - RobC