It is a superstition in India that black cats bring bad luck. However, The coat color of black cats is due to genetics. The high production levels of the pigment melanin cause it. This gene is a dominant gene trait, so it is passed along through the parent or parents. About 18% of the cat population is black. However, most black cats have splashes of white on them. Only about one out of twenty-two are entirely black. Scientific studies have shown that black cats are less prone to health problems and diseases. In the 17th century, medieval Europeans believed that demons and witches could transform into black cats, therefore starting this superstition that black cats are bad luck. Black cats tend to be good-natured and easy-going. They tend to be calm and tolerant of children and other animals. Black cats also tend to be vigilant and intelligent; however, there is no scientific evidence that black cats are more intelligent than regular cats.