I like hair, that is why I have long hair and a beard and we have Shih Tzu dogs that have lots and lots and lots of hair. All animals have hair at some point and in some form in their life even if it is fuzz on a newborn whale or the spines on a porcupine. Even insects can have hair. The leg hairs on hunting spiders and crickets act like ears picking up sound vibrations.
Tiny human hairs in our lungs and nasal passages can taste the air and sweep out impurities. These hairs are slow to die. Pathologists have noticed that nasal cilia contine to pulse for up to 21 hours after their human has died.
Just shampooed hair is lovely but dirty may be better. Oily hair absorbs the air pollutant ozone seven times more than clean hair. So don't wash your hair, let it clean the air (grin). Of course there is also good things to say about the absence of hair. Less maintenance comes to mind first but there are others. If you live in warm climates or stay in heated building most of the year, the warmth from you hair is not needed. Of course if you are an astronaut hair is a nuisance for sure. In the absence of gravity it just hangs in all directions. Guess either being bald or having an "Afro" would be best for living in zero gravity. This blog was based on an article in DISCOVER magazine. Now, go brush your lovely locks and have a great day, you hear?