As a reaction against the bans and hurdles affecting international adoption, scholars Elizabeth Bartholet and Paulo Barrozo claim that every child has a right to a family as a matter of basic human rights. This claim devalues heritage or "cultural" claims and emphasizes the child's existence as a human being rather than a "property" of specific nations or, for example, abusive caregivers.
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."
The majority of people state that their primary source of information about adoption comes from friends and family and the news media. Nevertheless, most people report the media provides them a favorable view of adoption; 72% indicated receiving positive impressions. There is, however, still substantial criticism of the media's adoption coverage. Some adoption blogs, for example, criticized Meet the Robinsons for using outdated orphanage imagery as did advocacy non-profit The Evan B. Donaldson Adoption Institute.
Concerning developmental milestones, studies from the Colorado Adoption Project examined genetic influences on adoptee maturation, concluding that cognitive abilities of adoptees reflect those of their adoptive parents in early childhood but show little similarity by adolescence, resembling instead those of their biological parents and to the same extent as peers in non-adoptive families.
Markedly different from the modern period, ancient adoption practices put emphasis on the political and economic interests of the adopter, providing a legal tool that strengthened political ties between wealthy families and created male heirs to manage estates. The use of adoption by the aristocracy is well documented; many of Rome's emperors were adopted sons. Adrogation was a kind of Roman adoption which required the adrogator to be at least 60 years old.
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.
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.