When it comes to hair texture, human hair can be very strait, very curly, or nearly anywhere in between (slightly wavy, very wavy etc.) Scientists have discovered several different gene pairs at several different chromosomal locations that influence hair texture in humans, therefore human hair texture can be described as a trait. In addition to the many gene pairs that can influence a person's hair texture, the environment can influence a person's hair texture as well. For example a person whose hair is slightly wavy on a dry day, might be more curly or frizzy hair on a humid day. Since hair texture is influenced by the environment as well as genes it is also considered a trait.