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).

Private domestic adoptions: under this arrangement, charities and for-profit organizations act as intermediaries, bringing together prospective adoptive parents and families who want to place a child, all parties being residents of the same country. Alternatively, prospective adoptive parents sometimes avoid intermediaries and connect with women directly, often with a written contract; this is not permitted in some jurisdictions. Private domestic adoption accounts for a significant portion of all adoptions; in the United States, for example, nearly 45% of adoptions are estimated to have been arranged privately.[83]
Identity is defined both by what one is and what one is not. Adoptees born into one family lose an identity and then borrow one from the adopting family. The formation of identity is a complicated process and there are many factors that affect its outcome. From a perspective of looking at issues in adoption circumstances, the people involved and affected by adoption (the biological parent, the adoptive parent and the adoptee) can be known as the "triad members and state". Adoption may threaten triad members' sense of identity. Triad members often express feelings related to confused identity and identity crises because of differences between the triad relationships. Adoption, for some, precludes a complete or integrated sense of self. Triad members may experience themselves as incomplete, deficient, or unfinished. They state that they lack feelings of well-being, integration, or solidity associated with a fully developed identity.[129]

Now it happens that some people are interested in the welfare and high development of the human race; but leaving aside those exceptional people, all fathers and mothers are interested in the welfare of their own families. The dearest thing to the parental heart is to have the children marry well and rear a noble family. How short-sighted it is then for such a family to take into its midst a child whose pedigree is absolutely unknown; or, where, if it were partially known, the probabilities are strong that it would show poor and diseased stock, and that if a marriage should take place between that individual and any member of the family the offspring would be degenerates.[39]

The adoptee population does, however, seem to be more at risk for certain behavioral issues. Researchers from the University of Minnesota studied adolescents who had been adopted and found that adoptees were twice as likely as non-adopted people to suffer from oppositional defiant disorder and attention-deficit/hyperactivity disorder (with an 8% rate in the general population).[135] Suicide risks were also significantly greater than the general population. Swedish researchers found both international and domestic adoptees undertook suicide at much higher rates than non-adopted peers; with international adoptees and female international adoptees, in particular, at highest risk.[136]
By 1979, representatives of 32 organizations from 33 states, Canada and Mexico gathered in Washington, DC to establish the American Adoption Congress (AAC) passing a unanimous resolution: "Open Records complete with all identifying information for all members of the adoption triad, birthparents, adoptive parents and adoptee at the adoptee's age of majority (18 or 19, depending on state) or earlier if all members of the triad agree."[161] Later years saw the evolution of more militant organizations such as Bastard Nation (founded in 1996), groups that helped overturn sealed records in Alabama, Delaware, New Hampshire, Oregon, Tennessee, and Maine.[162][163] Simultaneously, groups such as Origins USA (founded in 1997) started to actively speak about family preservation and the rights of mothers.[164] The intellectual tone of these recent reform movements was influenced by the publishing of The Primal Wound by Nancy Verrier. "Primal wound" is described as the "devastation which the infant feels because of separation from its birth mother. It is the deep and consequential feeling of abandonment which the baby adoptee feels after the adoption and which may continue for the rest of his life."[153]
Psychologists' findings regarding the importance of early mother-infant bonding created some concern about whether parents who adopt older infants or toddlers after birth have missed some crucial period for the child's development. However, research on The Mental and Social Life of Babies suggested that the "parent-infant system," rather than a bond between biologically related individuals, is an evolved fit between innate behavior patterns of all human infants and equally evolved responses of human adults to those infant behaviors. Thus nature "ensures some initial flexibility with respect to the particular adults who take on the parental role."[96]
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,[12] continued, in a limited and highly ritualistic form, so that an adopter might have the necessary funerary rites performed by a son.[13] China had a similar idea of adoption with males adopted solely to perform the duties of ancestor worship.[14]
The most recent adoption attitudes survey completed by the Evan Donaldson Institute provides further evidence of this stigma. Nearly one-third of the surveyed population believed adoptees are less-well adjusted, more prone to medical issues, and predisposed to drug and alcohol problems. Additionally, 40–45% thought adoptees were more likely to have behavior problems and trouble at school. In contrast, the same study indicated adoptive parents were viewed favorably, with nearly 90% describing them as "lucky, advantaged, and unselfish."[144]
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.[180][181]

Adoptions can occur either between related family members, or unrelated individuals. Historically, most adoptions occurred within a family. The most recent data from the U.S. indicates about half of adoptions are currently between related individuals.[78] A common example of this is a "stepparent adoption", where the new partner of a parent may legally adopt a child from the parent's previous relationship. Intra-family adoption can also occur through surrender, as a result of parental death, or when the child cannot otherwise be cared for and a family member agrees to take over.
Other studies provide evidence that adoptive relationships can form along other lines. A study evaluating the level of parental investment indicates strength in adoptive families, suggesting that parents who adopt invest more time in their children than other parents and concludes, "...adoptive parents enrich their children's lives to compensate for the lack of biological ties and the extra challenges of adoption."[94] Another recent study found that adoptive families invested more heavily in their adopted children, for example, by providing further education and financial support. Noting that adoptees seemed to be more likely to experience problems such as drug addiction, the study speculated that adoptive parents might invest more in adoptees not because they favor them, but because they are more likely than genetic children to need the help.[95]
The American model of adoption eventually proliferated globally. England and Wales established their first formal adoption law in 1926. The Netherlands passed its law in 1956. Sweden made adoptees full members of the family in 1959. West Germany enacted its first laws in 1977.[49] Additionally, the Asian powers opened their orphanage systems to adoption, influenced as they were by Western ideas following colonial rule and military occupation.[50] In France, local public institutions accredit candidates for adoption, who can then contact orphanages abroad, or ask for the support of NGOs. The system does not involve fees, but gives considerable power to social workers whose decisions may restrict adoption to standardized families (middle-age, medium to high income, heterosexual, Caucasian).[51]
Previous research on adoption has led to assumptions that indicate that there is a heightened risk in terms of psychological development and social relationships for adoptees. Yet, such assumptions have been clarified as flawed due to methodological failures. But more recent studies have been supportive in indicating more accurate information and results about the similarities, differences and overall lifestyles of adoptees.[125]