According to Chinese philosophy, the whole universe is controlled by two primal forces. These are Yin and Yang. Everything can be categorized according to this system: from people to furniture, and even countries. The balance of the universe, the Earth, a nation, and even the health and moods of individuals are determined by the balance or imbalance of Yin and Yang.
The ideal balance of Yin and Yan is depicted by the well-known black and white circle. As the Yang part (white) decreases, the Yin part (black) increases; when one is at its height, the other is at its lowest ebb. Often people assume that Yang is male and Yin female. This is not quite true. Although they are associated with opposite genders, each contains within itself the seed of the other. So, even though Yang is a masculine force, women can possess it. In such ways, Yin and Yang are opposing yet complementary principles. Neither is more important than the other and only together do they make a whole.
Everyone has his or her own balance of Yin and Yang.

Commonly Attributed Qualities
Yin People	Yang People
average weight or slender often tall smiling face like strong colors delicate health individualis introspective responsive psychic meditative intelligent independent solitary spiritual rebellious nonmaterialistic introverted	corpulent medium height healthy serious features self-preoccupied susceptible unstable emotionally fear failure confident conservative sociable hospitable optimistic active pragmatic efficient community oriented distrustful materialistic passionate

Each of the five elements have a positive and a negative side. Which of these is expressed in people depends on whether their animal sign is Yin or Yang.

Animal	Yin/Yang	Natural Element
rat ox tiger rabbit dragon snake horse goat monkey rooster dog pig	Yang Yin Yang Yin Yang Yin Yang Yin Yang Yin Yang Yin	water water wood wood wood fire fire fire metal metal metal water