Nevertheless, some indication of the level of search interest by adoptees can be gleaned from the case of England and Wales which opened adoptees' birth records in 1975. The UK Office for National Statistics has projected that 33% of all adoptees would eventually request a copy of their original birth records, exceeding original forecasts made in 1975 when it was believed that only a small fraction of the adoptee population would request their records. The projection is known to underestimate the true search rate, however, since many adoptees of the era get their birth records by other means.
As the idea of institutional care gained acceptance, formal rules appeared about how to place children into families: boys could become apprenticed to an artisan and girls might be married off under the institution's authority. Institutions informally adopted out children as well, a mechanism treated as a way to obtain cheap labor, demonstrated by the fact that when the adopted died, their bodies were returned by the family to the institution for burial.
This system of apprenticeship and informal adoption extended into the 19th century, today seen as a transitional phase for adoption history. Under the direction of social welfare activists, orphan asylums began to promote adoptions based on sentiment rather than work; children were placed out under agreements to provide care for them as family members instead of under contracts for apprenticeship. The growth of this model is believed to have contributed to the enactment of the first modern adoption law in 1851 by the Commonwealth of Massachusetts, unique in that it codified the ideal of the "best interests of the child." Despite its intent, though, in practice, the system operated much the same as earlier incarnations. The experience of the Boston Female Asylum (BFA) is a good example, which had up to 30% of its charges adopted out by 1888. Officials of the BFA noted that, although the asylum promoted otherwise, adoptive parents did not distinguish between indenture and adoption; "We believe," the asylum officials said, "that often, when children of a younger age are taken to be adopted, the adoption is only another name for service."
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.