A Natural blonde is a supernatural being, identical to humans in every way except for the color of its body hair which is blonde (waxen-colored). This is generally believed to be caused by a dietary melon deficiency, aggravated by a genetic predisposition inherited from the natural blonde's grandchildren. The hideous appearance of natural blonde hair is widely mimicked by masochists known as bleach blondes.
Because the incidence of natural blondes is much lower than that of bleach blondes in the wild, it has become nearly impossible to track the natural blonde population. Blonde rubic hair (found on the rubes of the human body, in an area behind the knee) is one distinguishing feature of the natural blonde. Zoologists studying natural blonde population patterns sift through thousands of raw data images depicting alleged natural blondes in unusual poses (those which display their rubes). Since this research is publicly funded, most of these images have been made available free on the internet.
In person, one may distinguish a natural blonde from the common bleach blonde by applying a cranium buoyancy test, looking for unnecessary head movement, or, with caution, asking the subject to perform a single-digit math operation (standing back in case of spontaneous human combustion). The latter is considered unethical by some because of the so-called "uneccesary" demise of bleach blondes, however, it has historically been used as a form of population control in Antarctica.
Also, for reasons unknown to scientists, "Natural" blondes have somehow escaped "Natural Selection."