Evolutionary theory holds that sexual attraction is crucial for humankind’s survival, as it underlies the desire to reproduce. For this reason, males and females try to look attractive to the other sex by walking, talking, and laughing in gendered ways. If girls see their mothers wearing make-up and high heels, they want to do likewise. According to evolutionary theory, the species’ need to reproduce is part of everyone’s genetic heritage, so young boys and girls practice becoming attractive to the other sex. This behavior ensures that they will be ready after puberty to find each other and that a new generation will be born, as evolution requires.