Adoption practices have changed significantly over the course of the 20th century, with each new movement labeled, in some way, as reform. Beginning in the 1970s, efforts to improve adoption became associated with opening records and encouraging family preservation. These ideas arose from suggestions that the secrecy inherent in modern adoption may influence the process of forming an identity, create confusion regarding genealogy, and provide little in the way of medical history.
The next stage of adoption's evolution fell to the emerging nation of the United States. Rapid immigration and the American Civil War resulted in unprecedented overcrowding of orphanages and foundling homes in the mid-nineteenth century. Charles Loring Brace, a Protestant minister became appalled by the legions of homeless waifs roaming the streets of New York City. Brace considered the abandoned youth, particularly Catholics, to be the most dangerous element challenging the city's order.
The practice of closed adoption (aka confidential or secret adoption), which has not been the norm for most of modern history, seals all identifying information, maintaining it as secret and preventing disclosure of the adoptive parents', biological kins', and adoptees' identities. Nevertheless, closed adoption may allow the transmittal of non-identifying information such as medical history and religious and ethnic background. Today, as a result of safe haven laws passed by some U.S. states, secret adoption is seeing renewed influence. In so-called "safe-haven" states, infants can be left, anonymously, at hospitals, fire departments, or police stations within a few days of birth, a practice criticized by some adoption advocacy organizations as being retrograde and dangerous.
In many jurisdictions the adopted person's full original birth certificate is cancelled and replaced with a fabricated post-adoption birth certificate which states that the child was born to the adoptive parents. This deception, when carried out, may continue with the adopted person for life and can be the cause for many well documented traumas experienced by the adopted person, including loss of identity, family history, culture, biological family (including not only biological parents but also siblings and extended family), family medical history and records, and increased risk of suicide, homelessness, incarceration, PTSD, depression, and anxiety.
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.
In Spain under Francisco Franco’s 1939–75 dictatorship the newborns of some left-wing opponents of the regime, or unmarried or poor couples, were removed from their mothers and adopted. New mothers were frequently told their babies had died suddenly after birth and the hospital had taken care of their burials, when in fact they were given or sold to another family. It is believed that up to 300,000 babies were involved. These system – which allegedly involved doctors, nurses, nuns and priests – outlived Franco’s death in 1975 and carried on as an illegal baby trafficking network until 1987 when a new law regulating adoption was introduced.
Similar mechanisms appear to be at work in the physical development of adoptees. Danish and American researchers conducting studies on the genetic contribution to body mass index found correlations between an adoptee's weight class and his biological parents' BMI while finding no relationship with the adoptive family environment. Moreover, about one-half of inter-individual differences were due to individual non-shared influences.
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 a similar idea of adoption with males adopted solely to perform the duties of ancestor worship.
Open adoption allows identifying information to be communicated between adoptive and biological parents and, perhaps, interaction between kin and the adopted person. Open adoption can be an informal arrangement subject to termination by adoptive parents who have sole custody over the child. In some jurisdictions, the biological and adoptive parents may enter into a legally enforceable and binding agreement concerning visitation, exchange of information, or other interaction regarding the child. As of February 2009, 24 U.S. states allowed legally enforceable open adoption contract agreements to be included in the adoption finalization.
Nevertheless, work on adult adoptees has found that the additional risks faced by adoptees are largely confined to adolescence. Young adult adoptees were shown to be alike with adults from biological families and scored better than adults raised in alternative family types including single parent and step-families. Moreover, while adult adoptees showed more variability than their non-adopted peers on a range of psychosocial measures, adult adoptees exhibited more similarities than differences with adults who had not been adopted. There have been many cases of remediation or the reversibility of early trauma. For example, in one of the earliest studies conducted, Professor Goldfarb in England concluded that some children adjust well socially and emotionally despite their negative experiences of institutional deprivation in early childhood. Other researchers also found that prolonged institutionalization does not necessarily lead to emotional problems or character defects in all children. This suggests that there will always be some children who fare well, who are resilient, regardless of their experiences in early childhood. Furthermore, much of the research on psychological outcomes for adoptees draws from clinical populations. This suggests that conclusions such that adoptees are more likely to have behavioral problems such as ODD and ADHD may be biased. Since the proportion of adoptees that seek mental health treatment is small, psychological outcomes for adoptees compared to those for the general population are more similar than some researchers propose.
Foster care adoption: this is a type of domestic adoption where a child is initially placed in public care. Many times the foster parents take on the adoption when the children become legally free. Its importance as an avenue for adoption varies by country. Of the 127,500 adoptions in the U.S. in 2000 about 51,000 or 40% were through the foster care system.
The research literature states adoptees give four reasons for desiring reunion: 1) they wish for a more complete genealogy, 2) they are curious about events leading to their conception, birth, and relinquishment, 3) they hope to pass on information to their children, and 4) they have a need for a detailed biological background, including medical information. It is speculated by adoption researchers, however, that the reasons given are incomplete: although such information could be communicated by a third-party, interviews with adoptees, who sought reunion, found they expressed a need to actually meet biological relations.