More recent research found that in a sample of mothers who had released their children for adoption four to 12 years prior, every participant had frequent thoughts of their lost child. For most, thoughts were both negative and positive in that they produced both feelings of sadness and joy. Those who experienced the greatest portion of positive thoughts were those who had open, rather than closed or time-limited mediated adoptions.
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.
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.
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.
These practices have become significant social and political issues in recent years, and in many cases the policies have changed. The United States, for example, now has the 1978 Indian Child Welfare Act, which allows the tribe and family of a Native American child to be involved in adoption decisions, with preference being given to adoption within the child's tribe.
In sum, reunions can bring a variety of issues for adoptees and parents. Nevertheless, most reunion results appear to be positive. In the largest study to date (based on the responses of 1,007 adoptees and relinquishing parents), 90% responded that reunion was a beneficial experience. This does not, however, imply ongoing relationships were formed between adoptee and parent nor that this was the goal.
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.
The biological relationship between a parent and child is important, and the separation of the two has led to concerns about adoption. The traditional view of adoptive parenting received empirical support from a Princeton University study of 6,000 adoptive, step, and foster families in the United States and South Africa from 1968 to 1985; the study indicated that food expenditures in households with mothers of non-biological children (when controlled for income, household size, hours worked, age, etc.) were significantly less for adoptees; step-children, and foster children, causing the researchers to speculate that, instinctively, people are less interested in sustaining the genetic lines of others. This theory is supported in another more qualitative study where in adoptive relationships marked by sameness in likes, personality, and appearance, both adult adoptees and adoptive parents report being happier with the adoption.
Attitudes and laws regarding adoption vary greatly. Whereas all cultures make arrangements whereby children whose birth parents are unavailable to rear them can be brought up by others, not all cultures have the concept of adoption, that is treating unrelated children as equivalent to biological children of the adoptive parents. Under Islamic Law, for example, adopted children must keep their original surname to be identified with blood relations, and, traditionally, women wear a hijab in the presence of males in their adoptive households. In Egypt, these cultural distinctions have led to making adoption illegal.
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.
Evidence about the development of adoptees can be supported in newer studies. It can be said that adoptees, in some respect, tend to develop differently from the general population. This can be seen in many aspects of life, but usually can be found as a greater risk around the time of adolescence. For example, it has been found that many adoptees experience difficulty in establishing a sense of identity.
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.
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."
Infant adoption during Antiquity appears rare. Abandoned children were often picked up for slavery and composed a significant percentage of the Empire's slave supply. Roman legal records indicate that foundlings were occasionally taken in by families and raised as a son or daughter. Although not normally adopted under Roman Law, the children, called alumni, were reared in an arrangement similar to guardianship, being considered the property of the father who abandoned them.
Adopting older children presents other parenting issues. Some children from foster care have histories of maltreatment, such as physical and psychological neglect, physical abuse, and sexual abuse, and are at risk of developing psychiatric problems. Such children are at risk of developing a disorganized attachment. Studies by Cicchetti et al. (1990, 1995) found that 80% of abused and maltreated infants in their sample exhibited disorganized attachment styles. Disorganized attachment is associated with a number of developmental problems, including dissociative symptoms, as well as depressive, anxiety, and acting-out symptoms. "Attachment is an active process- it can be secure or insecure, maladaptive or productive." In the UK some adoptions fail because the adoptive parents do not get sufficient support to deal with difficult, traumatized children. This is a false economy as local authority care for these children is extremely expensive.
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.