Sexual expression involves behaviors and feelings that reveal our sexual selves. It is a complex process that varies across cultures. Research relies on self-reports, which can be problematic. Two universal characteristics of attractiveness are youthfulness and health, though ideals differ depending on factors like gender, ethnicity, and culture. Sexual scripts organize our expressions through cultural, intrapersonal, and interpersonal components. Sexual fantasies, dreams, and masturbation are private expressions that can fulfill various functions.