Chinese and western Astrology are both systems of divination that are based on date and time of birth. And although both traditions rely heavily on symbols to communicate their theories, each differs substantially.
Here's a crash course in understanding the differences between the two systems. Quite often, people will identify with one more strongly, but still ascribe to some of the other tradition's beliefs -- mix and match at will!
Chinese Astrology divides astrological signs by years, whereas western Astrology separates them by months. Therefore, the Chinese believe that people born in the same year share the same traits, whereas westerners group people on a month-by-month basis. This difference in sensibilities makes sense for each culture, as eastern societies play great emphasis on generational differences, whereas western countries focus more on psychological ones.
The 12 zodiac signs discussed in Chinese Astrology derive from a myth. According to legend, when God was developing a calendar, he summoned all the creatures on Earth to participate in a race. The first twelve species to cross the finish line were awarded signs in the Chinese zodiac. Consequently, the Rat got first place through cunning and strategy, while the meticulous Pig came in last because it was continually distracted by niggling details.
Western Astrology, on the other hand, bases its 12 zodiac signs on the constellations that move through the sky throughout the 12 months of the year. Therefore, the month of January is associated with Capricorn because that constellation is directly overhead during that time, whereas the month of July is linked to Cancer because this is when the Crab is at its zenith.
Lunar vs. solar calendars
Chinese Astrology is based on the lunar calendar, which is arranged by the phases of the Moon. According to the lunar calendar, each month begins with a New Moon and lasts for approximately 29 days. The western calendar is organized according to Earth's orbit around the Sun. According to the western calendar, each month begins on a set date and can last between 28 and 31 days.
Chinese Astrology identifies the world as being comprised of five elements: Fire, Earth, Metal, Water and Wood. In the lunar calendar, each element is linked to a 2-year period, and governs the motivating forces in your life. Fire signs are inspired by excitement; Earth types are motivated to create secure foundations. People born under the Metal element are driven to create order, while Water types are compelled to form emotional bonds. People born under the Wood element are motivated to explore.
In western Astrology, four elements are identified: Fire, Earth, Air, and Water. Each element is associated with three zodiac signs, and governs the prevailing psychology of each group. According to western Astrology, signs governed by the Fire element are impulsive, while Earth element signs are practical. People born under Air signs are intellectually oriented, whereas Water signs are driven by emotion.
Lunar phases vs. modes
Chinese Astrology places great emphasis on the lunar phase of birth. This system of divination links a person's temperament with the phase of the Moon at the time of their birth. There are four types of lunar phases: New Moon, Waxing Moon, Full Moon and Waning Moon. New Moon types are adventurous and seek innovative environments. Waxing Moon people are hard-working and desired merit-based systems. Full Moon types are diplomatic and seek out environments where protocol is emphasized. Waning Moon people are introspective and desire peaceful surroundings.
Conversely, western Astrology identifies three zodiac sign qualities: Cardinal, Fixed, and Mutable. Each mode is linked to four signs. According to western Astrology, one's mode of birth determines how one operates in any given environment. Consequently, Cardinal signs seek acceptance by becoming leaders. Fixed types make their mark through hard work. Mutable signs form deep personal connections as a means to fit in.