In the U.S., the most common family unit consists of the immediate family, or the parents and children living under one roof. Most American children are taught to compete, through organized sports and education, as well as speak their minds and have confidence to stand up for what they believe in. American kids also typically leave their parents' homes around college-age. This can be a major culture shock to immigrant families who teach their children to respect and obey their parents at all costs, as well as for cultures who expect their kids to remain living at home until they get married. Many immigrant families also feature several generations living under one roof, with younger family members respecting the needs of and valuing the opinions of the elders.