Red hair (also referred to as auburn, ginger or titian) varies from a deep orange-red through burnt orange to bright copper. It is characterized by high levels of the reddish pigment pheomelanin and relatively low levels of the dark pigment eumelanin. People with red hair are often referred to as redheads. Approximately 1% to 2% of the human population has red hair. It occurs more frequently (between 2% and 6% of the population) in northern and western Europeans, and their descendants, and at lower frequencies throughout other parts of Europe, Asia and Africa. Red hair appears in people with two copies of a recessive gene on chromosome 16 which causes a change in the MC1R protein. It is associated with fair skin color, freckles, and sensitivity to ultraviolet light, as the mutated MC1R protein is found in the skin and eyes instead of the darker melanin. Cultural reactions have varied from ridicule to admiration; many common stereotypes exist regarding redheads, and they are often portrayed as the “fiery-tempered redhead”.