Adoption practices have changed significantly over the course of the 20th century, with each new movement labeled, in some way, as reform.[152] 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,[153][154] create confusion regarding genealogy,[155] 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.[26][27]

Some adoptees reject the idea of reunion. It is unclear, though, what differentiates adoptees who search from those who do not. One paper summarizes the research, stating, "...attempts to draw distinctions between the searcher and non-searcher are no more conclusive or generalizable than attempts to substantiate...differences between adoptees and nonadoptees."[169]
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.[167]

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]
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]

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[83] about 51,000 or 40% were through the foster care system.[84]
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]
Beyond the foundational issues, the unique questions posed for adoptive parents are varied. They include how to respond to stereotypes, answering questions about heritage, and how best to maintain connections with biological kin when in an open adoption.[97] One author suggests a common question adoptive parents have is: "Will we love the child even though he/she is not our biological child?"[98] A specific concern for many parents is accommodating an adoptee in the classroom.[99] Familiar lessons like "draw your family tree" or "trace your eye color back through your parents and grandparents to see where your genes come from" could be hurtful to children who were adopted and do not know this biological information. Numerous suggestions have been made to substitute new lessons, e.g., focusing on "family orchards."[100]
There are supporters of various lists, developed over many decades, and there are persons who find them lacking, created to support an agenda, or furthering division. All terminology can be used to demean or diminish, uplift or embrace. In addressing the linguistic problem of naming, Edna Andrews says that using "inclusive" and "neutral" language is based upon the concept that "language represents thought, and may even control thought."[190]