Embracing the Coolness of Curly Hair

A study conducted by Penn State University suggests that humans evolved with more hair on their heads, particularly curly hair, to cool off their growing brains. The research found that tightly coiled hair creates more distance and air between the scalp and the top of the hair, reducing the impact of solar heat radiation. The study used a thermal manikin to test different hair textures and found that tight curls were the most effective in cooling the head. While early humans with larger brains may have relied on other strategies to cope with heat, understanding the biophysical aspects of heat transfer through hair could provide insights into human physiology.