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.
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.
Europe's cultural makeover marked a period of significant innovation for adoption. Without support from the nobility, the practice gradually shifted toward abandoned children. Abandonment levels rose with the fall of the empire and many of the foundlings were left on the doorstep of the Church. Initially, the clergy reacted by drafting rules to govern the exposing, selling, and rearing of abandoned children. The Church's innovation, however, was the practice of oblation, whereby children were dedicated to lay life within monastic institutions and reared within a monastery. This created the first system in European history in which abandoned children did not have legal, social, or moral disadvantages. As a result, many of Europe's abandoned and orphaned children became alumni of the Church, which in turn took the role of adopter. Oblation marks the beginning of a shift toward institutionalization, eventually bringing about the establishment of the foundling hospital and orphanage.
Infertility is the main reason parents seek to adopt children they are not related to. One study shows this accounted for 80% of unrelated infant adoptions and half of adoptions through foster care. Estimates suggest that 11–24% of Americans who cannot conceive or carry to term attempt to build a family through adoption, and that the overall rate of ever-married American women who adopt is about 1.4%. Other reasons people adopt are numerous although not well documented. These may include wanting to cement a new family following divorce or death of one parent, compassion motivated by religious or philosophical conviction, to avoid contributing to overpopulation out of the belief that it is more responsible to care for otherwise parent-less children than to reproduce, to ensure that inheritable diseases (e.g., Tay–Sachs disease) are not passed on, and health concerns relating to pregnancy and childbirth. Although there are a range of possible reasons, the most recent study of experiences of women who adopt suggests they are most likely to be 40–44 years of age, currently married, have impaired fertility, and childless.
His solution was outlined in The Best Method of Disposing of Our Pauper and Vagrant Children (1859) which started the Orphan Train movement. The orphan trains eventually shipped an estimated 200,000 children from the urban centers of the East to the nation's rural regions. The children were generally indentured, rather than adopted, to families who took them in. As in times past, some children were raised as members of the family while others were used as farm laborers and household servants. The sheer size of the displacement—the largest migration of children in history—and the degree of exploitation that occurred, gave rise to new agencies and a series of laws that promoted adoption arrangements rather than indenture. The hallmark of the period is Minnesota's adoption law of 1917 which mandated investigation of all placements and limited record access to those involved in the adoption.