Adoption is a process whereby a person assumes the parenting of another, usually a child, from that person's biological or legal parent or parents. Legal adoptions permanently transfer all rights and responsibilities, along with filiation, from the biological parents to the adoptive parents. Unlike guardianship or other systems designed for the care of the young, adoption is intended to effect a permanent change in status and as such requires societal recognition, either through legal or religious sanction. Historically, some societies have enacted specific laws governing adoption, while others used less formal means (notably contracts that specified inheritance rights and parental responsibilities without an accompanying transfer of filiation). Modern systems of adoption, arising in the 20th century, tend to be governed by comprehensive statutes and regulations. History Antiquity Adoption for the well-born While the modern form of adoption emerged in the United States, forms of the practice appeared throughout history. The Code of Hammurabi, for example, details the rights of adopters and the responsibilities of adopted individuals at length. The practice of adoption in ancient Rome is well-documented in the Codex Justinianus. Markedly different from the modern period, ancient adoption practices put emphasis on the political and economic interests of the adopter, providing a legal tool that strengthened political ties between wealthy families and created male heirs to manage estates. The use of adoption by the aristocracy is well-documented: many of Rome's emperors were adopted sons. Adrogation was a kind of Roman adoption in which the person adopted consented to be adopted by another. Infant adoption during Antiquity appears rare. Abandoned children were often picked up for slavery and composed a significant percentage of the Empire's slave supply. Roman legal records indicate that foundlings were occasionally taken in by families and raised as a son or daughter. Although not normally adopted under Roman Law, the children, called alumni, were reared in an arrangement similar to guardianship, being considered the property of the father who abandoned them. Other ancient civilizations, notably India and China, used some form of adoption as well. Evidence suggests the goal of this practice was to ensure the continuity of cultural and religious practices; in contrast to the Western idea of extending family lines. In ancient India, secondary sonship, clearly denounced by the Rigveda, continued, in a limited and highly ritualistic form, so that an adopter might have the necessary funerary rites performed by a son. China had