Let me explain you how the zodiac works and the different componenents and aspects that are involved.
The Zodiac is divided in elements. The fire signs of Aries, Leo and Sagittarius constitute the impulse of duty. The earth signs of Taurus, Virgo and Capricorn represent the wealth impulse. Gemini, Libra and Aquarius indicate the pleasure principle and Cancer, Scorpio and Pisces, the occult and spiritual pathway.
The process of re-incarnation and karma may be evaluated by scrutinizing the geniture (horoscope) of an individual. The predominance of planets in, for example, Kama signs would indicate a current incarnation tending towards desire and fulfillment of a passionate nature. Depending on the strength and other dignities of the planets in question, the use of these energies, and whether or not spiritual growth would result, is then ascertained.
The categorization of human beings is not exactly a cut and dry process, as is generally being presented. Each zodiac sign in unique and the myriad of combinations need to be carefully balanced to assess the karmic grade of the present life. Of course, current high grades may not necessarily ensure high grades in future births. The resultant karma and their exhaustion need to be analyzed to see what benefits or lapses will accrue at the end of this incarnation. As we successively evolve through series of lives, we associate with the star signs under which we are born. In fact we express those very qualities inherent in the cosmic patterns.
Each of the signs of the zodiac is represented by a symbol or glyph, depicting the evolution of the soul through twelve different stages. The glyphs express the deeper more esoteric aspects of astrology and reveal inner evolutionary trends, as individuals and as parts of a vaster network of universal energies.