Although the institution of the adoption of children exists in most countries, there are differing views as to the principles which should govern adoption, both in procedure and in legal consequences. The legal status of an adoptive child may be different from that of a natural child, and he may have restricted rights of inheritance. Since the natural mother's or the parents' consent is usually necessary, the adoption process may be hindered, or the parents may reclaim the child later. Some foster parents discriminate when choosing children, often leaving the unintelligent, less attractive, deformed or racially unacceptable children. In rare cases foster parents prove to be inadequate. Others effect a sham 'adoption', acquiring children for a price from poor parents for use as servants or possibly for sexual exploitation.
Adoption first became institutionalized under the Greek and Roman civilizations, although the earliest records come from before those civilizations. Ancient civilizations used it to provide heirs, safeguard succession and meet the demands of ancestral worship. Most adoptions were in order to perpetuate the male line in a family, and the adopted were therefore usually male and often adult. Until recently it was the rights of the parents that were stressed. The Massachusetts Statute (1851) was the first to emphasize the welfare of adopted children. The adoption movement in its modern form began in the 19th century in the USA, Canada and New Zealand; the UK introduced adoption laws in 1926, and France in 1923. Adoption today is widely seen by agencies as a form of child care rather than as a service to infertile couples.