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Early results reveal that children adopted into families fare as well as those born into Susan Freivalds

When Matt McGue and his wife were preparing for the adoption of their daughters, Sammie and Elise, he was struck by how little solid information was available on adoption outcomes. “Most of what we heard was based on anecdote or stereotypes,” says McGue, a University of Minnesota psychology professor.

This has long been a complaint of couples considering adoption. Often adoption studies are flawed because of ways subjects are recruited. Some studies locate families through mental health clinics, which may bias the results toward troubled families. Others ask for volunteers, leading some to question whether results are skewed toward willing (and therefore, happy) participants.

Now, one of the most comprehensive studies of families ever undertaken is shedding light on the adoption experience. Called the Sibling Interaction and Behavior Study (SIBS), it was launched in 1999 by the University of Minnesota’s Center for Twin and Family Research. Funded by the National Institutes of Health, the SIBS study has two primary purposes: to examine how siblings interact and influence one another, and to see how family dynamics impact the psychological health of adolescents.

The SIBS study includes a significant percentage of adoptive families because of the unique research opportunity they offer. In families in which all members are related by birth, behavioral scientists cannot separate genetic from environmental influences on psychological characteristics. Scientists know that certain traits, including academic achievement, personality features, and risk of psychological disturbance, tend to “run in families.” But do these reflect a common genetic heritage or do the traits reflect the fact that siblings grew up together in the same family? One way to find out is to look at families with no common genetic component and see if the effects are still there.

“Surprisingly, if you look at the research, not many studies have asked about sibling relationships. SIBS is also one of the first studies to systematically explore adoptive families with a representative sample,” says Professor McGue, who heads the Minnesota study. As such, the SIBS study will have important insights about adoptive family dynamics.

Four hundred of the 600 families in the SIBS study were selected because they include at least one adopted child. Findings will be important to all families, no matter their composition. But because adoptive families make up a large percentage of the subjects, researchers will be able to answer questions specific to families formed through adoption:

  • Will I love the child I adopt as much as I would love a child I gave birth to? What if the child is of a different race?

  • How does it work to have both adopted and biological children in the same family?

  • How do one child’s problems affect the other kids in the family?

  • Is it important for an adopted child to live with a sibling of the same ethnicity?

  • Early findings

    With data in from just over one-third of the families, Dr. McGue has released preliminary findings. For adoptive families, the most significant are:

    There is virtually no difference in psychological functioning between children raised in adoptive families and those raised in biological families. In measures of delinquency, antisocial attitudes, aggression, substance abuse, and other problem behaviors, the differences between adopted children and children being raised by their biological families were insignificant. Measures of well-being, identity, academic achievement, and other positive characteristics were also virtually identical. These positive findings contradict earlier research that found adopted adolescents at greater risk for psychological problems than their non-adopted peers, SIBS researchers note. However, the average age of the adolescents in the study is only 15, so it is possible that differences between adopted and non-adopted individuals may emerge later.

    Sibling relationships appear unaffected by adoption. Relationships were equally close and loving among all kinds of sibling pairs (adopted-adopted, adopted-bio, and bio-bio). Although bio siblings thought of themselves as being more similar, this perceived similarity did not affect the quality of relationships between adoptive and biological siblings. Birth order was much more significant in sibling relationships than was adoptive status. The older sibling was almost always more powerful in the relationship, regardless of whether s/he had been adopted.

    3. In parent-child relationships, researchers identified some differences between adoptive and biological families. Parents and children felt as attached to each other in adoptive families as in biological families, but adopted children reported more conflict with parents than did biological offspring. This did not, however, result in greater behavior problems outside the home, as might have been expected.

    4. Despite the absence of genetic links, adoptive siblings are psychologically similar to one another in some significant ways. As would be expected, siblings by adoption showed no similarities in the kinds of personality traits that psychologists know to be largely genetic in origin, such as being shy or outgoing. In two areas of behavior, however, researchers identified surprising similarities among adoptive siblings. First, in academic achievement, adoptive siblings turned out to have comparable IQs (although not as similar as those of biological siblings), as well as similar academic motivation and achievement levels. This is likely attributable to parental influence. Adoptive siblings were also alike in regard to problem behaviors, such as smoking, alcohol use, and disobedience. Having an older sibling with problem behavior was highly predictive of such behavior in younger siblings. Thus, the research suggests that problem behavior is less a matter of parental influence than of sibling influence. It’s too early to tell if the adoptive status of an older sibling is a factor.

    Addressing limitations of earlier adoption research
    How valid are these findings? SIBS is breaking ground by addressing the limitations of earlier adoption research. The designs of many previous studies, particularly those with positive results, have been criticized for including mostly well-functioning families with few problems. The SIBS study is different in a number of ways:

    1. Families are recruited for the study through adoption agencies, not by requesting volunteers. To avoid the bias that comes with volunteers (who have been found to be psychologically healthier than non-volunteers), families are invited to participate, rather than offering to take part.
    Study participants are interviewed face-to-face. Problem behaviors that might not be elicited through a questionnaire are more likely to surface.

    3. SIBS maximizes participation by accommodating interviewees’ schedules, giving incentives, and thoroughly explaining the project and its importance.

    4. The inclusion of biological families in the study allows for identification of characteristics specific to adoptive families.

    5. Researchers are conducting brief assessments of families who choose not to participate to see if they differ from those who do. As it turns out, no difference in problem behavior levels has appeared between families who agreed to participate in the research compared to families who declined to take part: 26% of the study families said their adopted children had problem behaviors vs. 26.2% of non-participating families. The divorce rate, while low for both groups, is somewhat higher for study participants than for non-participants.

    Thus, McGue feels that the study group is fairly representative of adoptive families and that the findings will accurately portray families who adopt infants and toddlers through an adoption agency.

    Research study design
    Virtually every family in Minnesota who adopted an infant born from 1980 to 1993 through three statewide adoption agencies has been identified and contacted about participation. Families with at least two children close in age (within four years) are asked to participate, and about two-thirds have agreed to do so. A comparable group of biological families were identified from public birth records; about 50% have agreed to participate.

    Families in the study come to the University of Minnesota to participate in about 20 assessments. These focus on academic achievement, relationships with family and friends, mental health, and substance use. Teachers are also asked to complete questionnaires regarding the adolescents.

    More answers to come
    After all 600 participating families have been assessed, the SIBS database will be an important resource for researching a multitude of issues affecting adopted children and their families. Among the questions that could be answered:

  • How does being of a different ethnicity from one’s parents affect psychological well-being and behavior?

  • How important is it for a child to have a positive ethnic identity?

  • How important is talking about adoption to children?

  • What is the incidence of Attention Deficit/Hyperactivity Disorder (ADHD) in adopted children?
  • SIBS will provide findings of interest to all families, not only to those formed through adoption. The study examines relationships in the home and how they affect children’s behavior. Some questions to be answered include:

  • What’s the effect of an older sibling on a younger one?

  • Does growing up in the same home encourage or discourage smoking, drinking, or drug use?

  • Which behaviors of children are more influenced by siblings than by parents?

  • Do close relationships with siblings improve a child’s mental health?

  • How is sibling behavior affected by differences in age and gender?

  • How can we use this knowledge to prevent kids from getting into trouble?

  • Outlook

    It is always reassuring when research confirms what we know. Most of us know that adoptive families are as close and loving as those formed through birth. It’s important to note that SIBS findings to date are based on partial data and thus may be subject to change as the full quota of families is studied. Findings are also limited by the fact that assessments are taken at a single point in adolescent life. Will these positive indications hold when children leave home? SIBS researchers hope to secure funding to study the same families at three-year intervals until the children reach young adulthood. Stay tuned.

    Susan Freivalds is Editorial Director of Adoptive Families.

    ©Copyright 2002 Adoptive Families magazine. Reproduction in whole or in part without permission is prohibited.

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