What is the primary function of hair?

The primary function of hair is to protect the scalp and regulate body temperature. Hair on the scalp acts as a barrier, safeguarding the skin from harmful UV rays, dirt, and injury. It also helps in minimizing heat loss from the head, thereby playing a role in temperature regulation.

While aesthetic appeal is a significant aspect of hair in terms of styling and cultural expression, it is not the fundamental biological function. Similarly, although hair contributes to sensory activities by helping detect light touch, the role of hair as a sensory organ is secondary to its protective and thermoregulating functions. The enhancement of hair color, though relevant in the context of styling and beauty, does not reflect a primary biological purpose. Overall, the protective and thermoregulating roles highlight the essential functions of hair in human physiology.