In the U.K., 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.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.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 adoptees 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.These differences in development appear to play out in the way young adoptees deal with major life events. In the case of parental divorce, adoptees have been found to respond differently from children who have not been adopted. While the general population experienced more behavioral problems, substance use, lower school achievement, and impaired social competence after parental divorce, the adoptee population appeared to be unaffected in terms of their outside relationships, specifically in their school or social abilities. Effects on the original parents
Several factors affect the decision to release or raise the child.
The wide range of values reflects the paucity of information on the subject and demographic factors such as age; it is known that teenagers are more prone to having their adoptions disrupted than young children. Adoption by same-sex couples
Joint adoption by same-sex couples is legal in 34 countries as of March 2022, and additionally in various sub-national territories. Adoption may also be in the form of step-child adoption (6 additional countries), wherein one partner in a same-sex couple adopts the child of the other. Most countries that have same-sex marriage allow joint adoption by those couples, the exceptions being Ecuador (no adoption by same-sex couples), Taiwan (step-child adoption only) and Mexico (in one third of states with same-sex marriage). A few countries with civil unions or lesser marriage rights nonetheless allow step- or joint adoption. Parenting of adoptees
Parenting
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 people are less interested in sustaining the genetic lines of others.