• Regulation of sexual behavior: Sexual norms are various depending on time and culture. But standards of sexual behavior are clearly defined within the family circle. 
• Affection and companionship: Ideally, the family provides members with warm and intimate relationships. 
• Provision of social status: Children inherit ascribed statuses of family such as race and ethnicity. Family resources also affects children’s certain opportunity such as higher education.
 
Why nuclear family? 
• In the most known societies today, the nuclear family is at the core. (Thailand?) 
• It is good at social tasks mentioned above. (Regulating sexual relations, reproduction, socialization, and economic co-operation between the couple). 
• Its size is good for social mobility in an industrialized era.