Racial classifications in Brazil are based on skin color and on other physical characteristics such as facial features, hair texture, etc. This is a poor scientific indication of ancestry, because only a few genes are responsible for someone's skin color: a person who is considered White may have more African ancestry than a person who is considered Black, and vice versa. But, as race is a social construct, these classifications relate to how people are perceived and perceive themselves in society. In Brazil, class and economic status also affect how individuals are perceived.