Why do people have hair in the skin?

People have hair on their skin primarily for insulation and protection. Hair helps to regulate body temperature by trapping heat and can also provide a barrier against environmental factors, such as UV radiation and foreign particles. Additionally, hair follicles are associated with sensory receptors, enhancing the skin's ability to detect touch and changes in the environment. Evolutionarily, hair may have also played a role in social signaling and communication among humans.