The nobility of the Germanic, Celtic, and Slavic cultures that dominated Europe after the decline of the Roman Empire denounced the practice of adoption. In medieval society, bloodlines were paramount; a ruling dynasty lacking a "natural-born" heir apparent was replaced, a stark contrast to Roman traditions. The evolution of European law reflects this aversion to adoption. English Common Law, for instance, did not permit adoption since it contradicted the customary rules of inheritance. In the same vein, France's Napoleonic Code made adoption difficult, requiring adopters to be over the age of 50, sterile, older than the adopted person by at least 15 years, and to have fostered the adoptee for at least six years. Some adoptions continued to occur, however, but became informal, based on ad hoc contracts. For example, in the year 737, in a charter from the town of Lucca, three adoptees were made heirs to an estate. Like other contemporary arrangements, the agreement stressed the responsibility of the adopted rather than adopter, focusing on the fact that, under the contract, the adoptive father was meant to be cared for in his old age; an idea that is similar to the conceptions of adoption under Roman law.
Family preservation: As concerns over illegitimacy began to decline in the early 1970s, social-welfare agencies began to emphasize that, if possible, mothers and children should be kept together. In the U.S., this was clearly illustrated by the shift in policy of the New York Foundling Home, an adoption-institution that is among the country's oldest and one that had pioneered sealed records. It established three new principles including "to prevent placements of children...," reflecting the belief that children would be better served by staying with their biological families, a striking shift in policy that remains in force today.
The language of adoption is changing and evolving, and since the 1970s has been a controversial issue tied closely to adoption reform efforts. The controversy arises over the use of terms which, while designed to be more appealing or less offensive to some persons affected by adoption, may simultaneously cause offense or insult to others. This controversy illustrates the problems in adoption, as well as the fact that coining new words and phrases to describe ancient social practices will not necessarily alter the feelings and experiences of those affected by them. Two of the contrasting sets of terms are commonly referred to as positive adoption language (PAL) (sometimes called respectful adoption language (RAL)), and honest adoption language (HAL).
Evidence about the development of adoptees can be supported in newer studies. It can be said that adoptees, in some respect, tend to develop differently from the general population. This can be seen in many aspects of life, but usually can be found as a greater risk around the time of adolescence. For example, it has been found that many adoptees experience difficulty in establishing a sense of identity.
Externally focused theories, in contrast, suggest that reunion is a way for adoptees to overcome social stigma. First proposed by Goffman, the theory has four parts: 1) adoptees perceive the absence of biological ties as distinguishing their adoptive family from others, 2) this understanding is strengthened by experiences where non-adoptees suggest adoptive ties are weaker than blood ties, 3) together, these factors engender, in some adoptees, a sense of social exclusion, and 4) these adoptees react by searching for a blood tie that reinforces their membership in the community. The externally focused rationale for reunion suggests adoptees may be well adjusted and happy within their adoptive families, but will search as an attempt to resolve experiences of social stigma.