Which physical characteristic is NOT associated with yin?

Yin is often characterized by qualities that are opposite to those associated with yang. Key characteristics of yin include softness, coldness, and ease, which all reflect the nature of yin as embodying passive, receptive, and nurturing qualities.

The characteristic of forcefulness, which is associated with exertion, strength, and activity, is representative of yang rather than yin. Yang qualities are typically dynamic and vigorous, contrasting sharply with the gentler, more subtle attributes of yin. Therefore, identifying forcefulness as not associated with yin aligns with the fundamental principles of Traditional Chinese Medicine, where yin represents the nurturing and more passive elements, while yang represents the active and aggressive aspects.