Submitted to Twin Research and
Human Genetics—February 9, 2006
Early Growth and Development Study
Running Head: EARLY GROWTH AND DEVELOPMENT STUDY
The Early Growth and Development Study: A Prospective Adoption Design
Leslie D. Leve1,2
Oregon Social Learning Center
Jenae M. Neiderhiser3
George Washington University
Xiaojia Ge4
University of California, Davis
Laura V. Scaramella5
University of New Orleans
Rand D. Conger4
University of California, Davis
John B. Reid2
Oregon Social Learning Center
Daniel S. Shaw6
University of Pittsburgh
David Reiss3
George Washington University
1
Submitted to Twin Research and
Human Genetics—February 9, 2006
Early Growth and Development Study
1
Corresponding author. Phone: 541-485-2711. Fax: 541-485-7087. E-mail: [email protected].
2
Oregon Social Learning Center, 160 East 4th Avenue, Eugene, OR 97401-2426, USA
3
Center for Family Research, George Washington University, 2300 K Street, N.W., 3rd Floor,
Washington, DC 20037, USA
4
Department of Human and Community Development, University of California, 202 Cousteau
Place, Suite 175, Davis, CA 95616, USA
5
University of New Orleans, Department of Psychology, 2001 Geology and Psychology
Building, New Orleans, LA 70148, USA
6
University of Pittsburgh, Department of Psychology, 4422 Sennott Square, Pittsburgh, PA
15260, USA
2
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Early Growth and Development Study
3
Abstract
The Early Growth and Development Study is a prospective adoption study of birth parents,
adoptive parents, and adopted children that was initiated in 2003 (targeted N = 350 triads). The
primary study aims include an examination of family relationships that mediate or moderate the
expression of genetic influences and the identification of specific family processes that could
serve as malleable targets for intervention. Participants in the study are recruited following the
birth of the child through adoption agencies located throughout the United States. Assessments
occur in 6-month intervals until age 3 years. Data collection includes the following primary
constructs: infant/toddler temperament, social behavior, and health; birth and adoptive parent
personality characteristics, psychopathology, competence, stress, and substance use; adoptive
parenting and marital relations; and prenatal exposure to drugs and maternal stress. Preliminary
analyses suggest the representativeness of the sample and minimal confounding effects of current
trends in adoption practices, including openness and selective placement.
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The Early Growth and Development Study: A Prospective Adoption Design
Primary Research Focus and Study Rationale
The primary goal of the Early Growth and Development Study (EGDS) is to examine
specific features of family relationships that mediate or moderate the expression of genetic
influences as they appear in infancy and subsequently unfold later in development. The
investigation of Genotype x Environment (GxE) interaction effects and genotype–environment
(GE) correlations can provide crucial information about malleable environmental processes that
might reduce adverse genetic risk. Thus, a second goal of the EGDS is to systematically identify
specific family processes and maladaptive conditions that could serve as malleable targets for
intervention.
Longitudinal and cross-sectional studies have shown that heritable child characteristics
influence parents’ behavior towards their children (Dunn et al., 1986; Reiss et al., 2000). For
example, heritable hostile behavior in adolescent adoptees has been shown to evoke harsh
disciplinary practices in adoptive parents (Ge et al., 1996). Evocative or environmentally
mediated effects have also been found to be prominent in the preschool and school entry periods
(Deater-Deckard, 2000; Deater-Deckard & O'Connor, 2000). In addition, family context and
parenting process play a central role in the moderation of genetic influences on child behavior.
Large GxE interaction effects have been found for the development of conduct disorder and
aggression in adolescence, antisocial personality disorder in adults, and depression in women
(Button et al., 2005; Cadoret, 1982; Cadoret & Cain, 1981; Cadoret et al., 1983, 1995, 1996).
Such GxE interactions are likely present in early childhood, when child behavior has proven to
be amenable to intervention (Olds et al., 2005); however, adoption studies prospectively
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examining social processes during this period are rare, with the EGDS and the Colorado
Adoption Project (Plomin & DeFries, 1985) being the only such studies to date.
In addition, most data on evocative influences are derived from twin studies. Because
twin offspring share 50% of their individual difference genes with each parent, it is difficult to
ascertain from twin studies whether evocative effects of heritable features in the child have
comparable effects in caretakers who do not share the same genes. The adoption design is a
powerful method for estimating these effects because adoption is a natural experiment in which
children are reared in families where they are genetically unrelated to their caretakers (Haugaard
& Hazan, 2003). By focusing on family processes beginning in infancy, the EGDS provides a
unique opportunity to detect GE processes at the earliest point of expression.
In the adoption design, similarities between birth parents and their adopted-away children
suggest genetic influences (due to shared genes and a lack of shared rearing environments). The
intrauterine influences that can confound these interpretations are carefully monitored in the
EGDS. Similarities between adoptive parents and adopted children likely reflect environmental
processes (due to shared rearing environments and the lack of shared genes). The conceptual
model for the EGDS rests on these basic premises and incorporates the following hypotheses: (a)
that adoptive parenting behaviors are influenced by contextual factors (e.g., parental
psychopathology, marital conflict, and perceived economic distress), (b) that contextual factors
moderate genetic influences on child behavior, (c) that adoptive parenting behaviors mediate and
moderate genetic influences on child behavior, (d) that child characteristics and adoptive
parenting behavior show change and continuity across time points, and (e) that these
relationships hold when potential violations of the adoption design assumptions are controlled
(e.g., selective placement, intrauterine exposure, openness in adoption). One depiction of this
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conceptual model, showing how environmental processes serve to mediate and moderate adverse
genetic influences on child problem behavior and exacerbate poor developmental outcomes over
time, is presented in Figure 1.
______________________________
Insert Figure 1 About Here
______________________________
Recruitment Methods
The EGDS recruitment procedures were designed to accomplish the following: (1) to
reduce the likelihood of recruiting only one member of the adoption triad; (2) to minimize
potential ethical concerns by not initiating contact until after the period of revocation; (3) to
minimize the probability of information transfer across participants, including adoption agencies;
and (4) to recruit a sample that would contain ethnic diversity and diversity in the level of
adoption openness. This complicated recruitment strategy entailed the collaboration of three
recruitment sites: Mid-Atlantic (George Washington University), West/Southwest (University of
California, Davis), and Pacific Northwest (Oregon Social Learning Center). Thirty-six adoption
agencies were drawn from 17 states surrounding the three sites to assist in sample recruitment.
These agencies reflect the full range of U.S. adoption agencies: public, private, religious, secular,
those favoring open adoptions, and those favoring closed adoptions. Because adoption agencies
often work in multiple states, the EGDS sample consists of birth parents and adoptive families
from more than 40 states. The project employs separate birth parent and adoptive family
recruiters to ensure that no information about either party is transferred to the other members of
the triad. We maintain this separation through all stages of the study, including assessment.
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Inclusion criteria. To be eligible for recruitment into the EGDS, birth parents must have
worked with one of the participating adoption agencies to complete a domestic adoption
placement to a nonrelative adoptive family within 3 months postpartum. All types of adoptive
families are eligible for study enrollment (e.g., same-sex parents, single parents, and hearingimpaired parents). To minimize potential confounds, two recruitment exclusion criteria were
used: infants with major medical problems identified in the first 3 months of life and
birth/adoptive parents who are unable to understand English.
Agency liaison. Each adoption agency appoints a liaison from their organization to
perform the initial stages of recruitment into the study. Liaisons receive recruitment training by
the EGDS staff, and agencies are provided an honorarium for their efforts assisting with
recruitment. Recruitment proceeds through multiple steps. First, liaisons identify adoptions that
meet the EGDS inclusion criteria (described above). Second, approximately 4 weeks
postplacement, the liaison mails a letter on agency letterhead describing the study to each
eligible adoptive family. A study brochure and a postcard are included for the adoptive family to
return if they do not wish to be contacted. Third, two weeks after the mailing, liaisons call the
birth mothers linked to the adoptive families that did not return a postcard (83% of the adoptive
family letters mailed). During the phone call with the birth mother, the liaison briefly describes
the study and asks for permission to have a recruiter from the study contact her directly. To date,
liaisons have been unable to contact 31% of the eligible birth mothers; 98% of the birth mothers
contacted by liaisons have agreed to be contacted directly by the study. Finally, the liaison
provides the phone numbers of the birth mother and the adoptive family to the EGDS recruiters.
Birth mothers. Once a birth mother has consented to being contacted, a birth parent
recruiter calls her and attempts to recruit her into the study. To date, the EGDS recruiters have
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Early Growth and Development Study
8
recruited birth mothers with a 98% success rate. If the birth mother agrees to participate, she is
sent an informed consent form and additional study information. One week later, the recruiter
calls the birth mother to review the consent form and answer questions. Once the birth mother
returns a signed consent form via postage-paid mail, she is considered an active study
participant.
Adoptive families. After recruiting the birth mother, an adoptive family recruiter attempts
to recruit the adoptive family. The adoptive family recruiter contacts the adoptive family by
phone, reminds the family of the letter sent previously, and provides detailed information about
the study and about participation. If the adoptive parents agree to participate, they are sent
informed consent forms and additional study information. Like birth mothers, adoptive parents
are considered recruited once they return a signed informed consent form. To date, the EGDS
recruiters have recruited adoptive families with a 76% success rate.
Birth fathers. Most adoption studies incorporate information about birth fathers only from
hospital records or similar reports. Thus, genetic contributions to child behavior in previous
adoption studies have been estimated primarily from knowledge of only 50% of the genetically
transmitted characteristics (i.e., birth mother characteristics only). To date, the EGDS has the
largest sample of directly studied birth fathers in an adoption study and is the only study to
assess birth fathers longitudinally; we have recruited and assessed birth fathers in 32% of our
participating triads. Project staff members attempt to recruit the birth father using the procedures
outlined in the birth mother recruitment section. If the liaison does not know or cannot reach the
birth father, a project staff member asks the birth mother if she is willing to answer some
questions about the birth father to help the study locate him. In such cases, the birth mother is
asked about the birth father’s identity, her ability to contact him, and any personal concerns
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Early Growth and Development Study
9
about potential harm from the birth father should she provide the study with his contact
information. If a birth mother does not perceive harm and agrees to provide contact information,
she completes a consent form releasing his information to the study. When the liaison does not
provide the recruiters with information about a birth father, that birth father is only contacted if
the birth mother has provided this consent.
Sample Description
The EGDS sample consists of adoptive children who were placed with a nonrelative,
adoptive family within 3 months postpartum (M age at placement = 3 days, SD = 6 days). The
birth parents and adoptive parents of these children also participate in the study. As of December
2005, 300 adoption triads had been enrolled in the EGDS. Adoptive children’s birth dates range
from 1/1/03 to 12/31/05. Recruitment is ongoing, with the complete sample estimated to include
350 triads: 350 adoptive children (approximately half girls), 350 sets of adoptive parents, 350
birth mothers, and 115 birth fathers (34% of the triads). Descriptive statistics on triads who had
completed at least one in-person assessment by December 31, 2005 are presented below.
The average ages of birth parents when the adoptive child was born were 24 years (SD =
6 years) for mothers and 26 years (SD = 7 years) for fathers. The average age of adoptive parents
when the adoptive child was born was 38 years (SD for mothers = 5 years; SD for fathers = 6
years). The sample is primarily Caucasian (72% of birth mothers, 79% of birth fathers, 91% of
adoptive mothers, and 88% of adoptive fathers), with African Americans (8%) and biracial
individuals (8%) comprising the majority of the non-Caucasian participants. Birth mothers and
birth fathers had a mean education level of a high school degree, and adoptive mothers and
fathers had a mean education level of a college degree. The median annual household income
was $15,000 for birth mothers, $21,000 for birth fathers, and $100,000 for adoptive families. On
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average, birth mother, birth father, and adoptive family households were each comprised of 3 to
4 individuals (M = 3.7, 3.5, and 3.7, respectively). Adoptive families had been married an
average of 11.8 years (SD = 5.4 years). As indicated by these demographic statistics, the
discrepancy in sociodemographic characteristics often found between birth and adoptive parents
was corroborated in the EGDS, suggesting the utility of adoption as an intervention on the
sociodemographic environments of young children.
Data Collection
Measurement for the EGDS has been guided by four principles: (1) adherence to a
theoretical model guiding the domains of assessment, (2) similar measurement of birth and
adoptive parent characteristics, (3) adoptive family completion of three primary assessments to
allow for curvilinear estimates of change, and (4) utilization of a multimethod, multiagent
assessment strategy. The assessment includes questionnaires, in-person interviews, telephone
interviews, and standardized testing for birth and adoptive parents and observational interactions
for adoptive families. Medical records for birth parents and adopted children are also collected.
The interviews include interviewer-administered questions, which create a context whereby the
interviewer can establish rapport with the participant, and computer-assisted personal interviews
(CAPI) that are completed privately by participants to facilitate confidentially and honesty of
responses. Birth parents are assessed in person at 3–6 months and 18 months postpartum and via
telephone at 12, 22, and 30 months. Adoptive families are assessed in person at 9, 18, and 27
months and via telephone at 6, 12, 22, and 36 months. In-person assessments last approximately
2.5 hr, and telephone interviews last approximately 20 min. To prevent the project from serving
as a conduit of information between birth and adoptive families, different interviewers conduct
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the birth parent and the adoptive family assessments within a triad. A listing of the measures
administered is presented in Table 1.
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Insert Table 1 About Here
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In-person assessments. Birth parent in-person interviews are conducted in a location
convenient for the participant, most often in his/her home. Both interviews include CAPI
questions interviewer-administered questions and mailed questionnaires (completed prior to the
interview). During first interview (3–6 months), birth mothers complete a Pregnancy History
Calendar about their activities and events during their pregnancy by each interval/trimester. Once
this calendar of salient events is completed, birth mothers use CAPI to report about drug use and
other behaviors during pregnancy. The second interview (18 months) is similar to the first
interview with a few exceptions. The most significant additions to the second in-person
assessment are the collection of detailed diagnostics using the Composite International
Diagnostic Interview (Kessler & Üstün, 2004) and the assessment of intelligence using two
subscales from the Wechsler Adult Intelligence Scale (Wechsler, 1997). Birth parents also
complete a CAPI version of the antisocial personality and conduct disorder sections from the
Diagnostic Interview Schedule (Robins et al., 2000).
The three adoptive family in-person assessments (9, 18, and 27 months) are conducted in
the families’ home. Assessments consist of questionnaires sent to the adoptive parents for
completion prior to the interview, CAPI questions completed during the visit, and videotaped
interactions of the child, of each parent with the child, and of the parents together. The
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interactive tasks are designed to measure child behavior, temperament, and parenting using a set
of developmentally appropriate stimuli.
Telephone interviews. Phone interviews are coordinated to occur in between the in-person
assessments as a means of maintaining contact and rapport with participants. The three birth
parent phone interviews focus primarily on general well-being and on the ongoing relationship
with the adoptive family and the adoption agency. In addition, to improve estimates of genetic
transmission of behavior by increasing information about nonparticipating birth fathers, each
birth mother reports on the birth father’s characteristics. To date, we have collected this
information on 93% of the participating adoption triads. Correlations between birth father selfreports and birth mother reports of the birth father suggest the validity of this approach; withinconstruct correlations ranged from .45 to .61. The four adoptive family phone interviews focus
primarily on the ongoing relationship with the birth parents and the agency, on general wellbeing, and on the adopted child’s daily behavior and parenting.
Preliminary Analyses
Participant recruitment and data collection are still underway. The preliminary results
presented here are based on the 211 triads who have completed the first in-person assessment.
Analyses focus on two sets of questions: an investigation of sample representativeness and an
investigation of adoption practices.
Sample representativeness. We sought to examine whether the EGDS sample was
representative of the population from which it was drawn. To assist with this, each participating
adoption agency recorded the education, income, and age of all birth and adoptive parents who
met the EGDS inclusion criteria and completed an adoption plan through their agency during the
EGDS enrollment period. We compared the demographic information between triads who
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Early Growth and Development Study
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participated in the EGDS with those of the eligible, nonparticipants. As is shown in Table 2, 2 of
11 comparisons reached statistical significance, and they proved trivial in practical terms (i.e.,
compared to nonparticipants, participating adoptive mothers achieved slightly higher educational
levels and participating birth fathers were slightly younger in age). There were no significant
demographic differences between birth mothers for whom birth fathers were recruited and birth
mothers for whom birth fathers were not recruited. These comparisons suggest the
representativeness of the EGDS sample to the population from which it was drawn.
______________________________
Insert Table 2 About Here
______________________________
Because sample recruitment was spread across three sites, regional differences in sample
characteristics were examined. Next, we compared birth mother, birth father, adoptive mother,
and adoptive father education level, income, and age by region. Of the 33 comparisons, only one
was significant (p < .05): adoptive father’s education was slightly higher in the sample recruited
by the Pacific Northwest site than in the sample recruited by the West/Southwest site. The ethnic
distribution of participants was also similar across regions. Taken together, these preliminary
analyses provide greater confidence of the representativeness of the EGDS sample and the
generalizability of study results.
Adoption practices. The adoption design rests on several assumptions about the separate
influences of genetic and environmental influences on child development. For example, once
intrauterine factors have been considered, similarities between the birth parent and adoptive child
can be assumed to result from genetic factors. Trends in adoption practices such as selective
placement (agency matching of birth and adoptive parent characteristics) and openness (contact
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and knowledge between birth and adoptive families) can pose a threat to these assumptions and
can bias model estimates. For example, adoptive children might be more likely to resemble their
birth parents (inflating genetic estimates) if birth parents are in direct contact with the child.
Thus, we examined the variation in two aspects of the adoption process—openness and selective
placement—with our preliminary sample of 211 triads and then examined whether systematic
variation in these characteristics biased our model estimates.
The level of openness was carefully measured by asking birth mothers and adoptive
mothers and fathers to report on the amount of contact and knowledge between them. Responses
were categorized into seven discrete categories: very closed (no information about the adoptive
parents/birth parents), closed (only general information that the agency provided), mediated
(written communication only, conducted through an agency), semi-open (exchange of
letters/emails, cards, and pictures but no face-to-face contact), open (visits one to three times per
year and communication semiregularly by phone, mail, or E-mail), quite open (visits about every
other month and frequent communication by phone, mail, or E-mail), and very open (visits at
least once monthly and communication several times a month by phone, mail, or E-mail). The
prevalence of each level of openness as rated by birth and adoptive parents is shown in Table 3.
Results suggest significant variation in openness across the sample. In addition, birth mothers,
adoptive mothers, and adoptive fathers were in strong agreement about the level of openness (r =
.72 - .87).
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Insert Table 3 About Here
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An openness composite that included birth mother, adoptive mother, and adoptive father
report of openness (described above), the level of contact between the birth and adoptive parents
(5 scales ranging from 1 [Never] to 5 [Daily]), and the extent of knowledge about each other (6
scales ranging from 1 [A lot] to 4 [Nothing]) was constructed (14 variables; α = .85). Preliminary
analyses suggest that less than 8% of the correlations between this openness composite and
primary birth parent and adoptive family measures were significant, suggesting negligible impact
of openness on model estimates.
To begin an examination of the potential effects of selective placement, birth parent
characteristics were correlated with adoptive family characteristics that were unlikely to be
influenced by evocative effects (e.g., demographic characteristics). Importantly, only 8% of the
adoptive parent–birth parent correlations were statistically significant, none of which occurred
within the same domain (e.g., adoptive father age was correlated with birth father education
rather than with birth parent age). Thus, systematic selective placement or bias due to the level of
openness has not been detected in the EGDS sample.
Future Plans
The full EGDS sample will be recruited by April 2006, and in-person assessments will be
completed by April 2008. We will continue to monitor and evaluate the sample
representativeness and adoption practices while testing the study’s primary hypotheses of the
mediating and moderating role of the environment on the expression of genetic influences. In
addition, we are exploring opportunities to increase the sample size, genotype the sample, and
continue assessments through school entry to study the unfolding of GE processes later in
development. Further, we hope to add measures of hypothalamic-pituitary-adrenal axis (a
neuroendocrine system involved in the regulation of and reaction to stress) functioning to
Submitted to Twin Research and
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Early Growth and Development Study
explore additional mechanisms of GxE interaction and to develop meaningful markers for the
effects of psychosocial interventions on gene expression.
16
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Acknowledgements
This project was supported by grant 5 R01 HD 42608 from the National Institute of Child
Health and Human Development and the National Institute on Drug Abuse (David Reiss, MD,
PI). We are indebted to the late Remi Cadoret for his insightful contributions to the
understanding of GxE interaction and for his commitment to the EGDS project from its onset. In
addition, we are grateful to participating adoption agency directors and staff, without whom this
work would not have been possible. Other key contributors to the project include our project
officer, Lisa Freund; our Advisory Board; the lead recruiters, Amy Whitesel, Danielle Guerrero,
and David Martin; the site supervisors, Anna Suski, Denise Ford, Laura Kwako, and Roline
Milfort; the biostatistics team, Sam Simmens and Karen Jones; and the dozens of other EGDS
team members who contributed to recruitment, data collection, and data management efforts.
Additional thanks go to Amber Johnson for assistance with the data analyses and to Matthew
Rabel for editorial assistance.
Submitted to Twin Research and
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References
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dysfunction interacts with genes in the causation of antisocial symptoms. Behavior
Genetics, 35, 115–120.
Cadoret, R. J. (1982). Genotype–environment interaction in antisocial behavior. Psychological
Medicine, 12, 235–239.
Cadoret, R. J., & Cain, C. A. (1981). Genotype–environmental interaction in antisocial behavior.
Psychological Medicine, 12, 235–239.
Cadoret, R. J., Cain, C. A., & Crowe, R. R. (1983). Evidence for gene–environment interaction
in the development of adolescent antisocial behavior. Behavior Genetics, 13, 301–310.
Cadoret, R. J., Winokur, G., Langbehn, D., Troughton, E., Yates, W. R., & Stewart, M. A.
(1996). Depression spectrum disease. I: The role of gene–environment interaction.
American Journal of Psychiatry, 153, 892–899.
Cadoret, R. J., Yates, W. R., Troughton, E., Woodworth, G., & Stewart, M. A. (1995). Genetic–
environmental interaction in the genesis of aggressivity and conduct disorders. Archives
of General Psychiatry, 52, 916–924.
Deater-Deckard, K. (2000). Parenting and child behavioral adjustment in early childhood: A
quantitative genetic approach to studying family processes. Child Development, 71, 468–
484.
Deater-Deckard, K., & O'Connor, T. G. (2000). Parent–child mutuality in early childhood: Two
behavioral genetic studies. Developmental Psychology, 36, 561–570.
Dunn, J., Plomin, R., & Daniels, D. (1986). Consistency and change in mothers' behavior
towards young siblings. Child Development, 57, 348–356.
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Ge, X., Conger, R. D., Cadoret, R. J., Neiderhiser, J. M., Yates, W., Troughton, E., et al. (1996).
The developmental interface between nature and nurture: A mutual influence model of
child antisocial behavior and parent behaviors. Developmental Psychology, 32, 574–589.
Haugaard, J. J., & Hazan, C. (2003). Adoption as a natural experiment. Development and
Psychopathology, 15, 909–926.
Kessler, R. C., & Üstün, T. B. (2004). The World Mental Health (WMH) Survey Initiative
version of the World Health Organization (WHO) Composite International Diagnostic
Interview (CIDI). International Journal of Methods in Psychiatric Research, 13, 93–121.
Olds, D. L., Robinson, J., Song, N., Little, C., & Hill, P. (2005). Reducing risks for mental
disorders during the first five years of life: A review of the literature. Rockville, MD:
Substance Abuse and Mental Health Services Administration.
Plomin, R., & DeFries, J. C. (1985). Origins of individual differences in infancy: The Colorado
Adoption Project. Orlando, FL: Academic Press.
Reiss, D., Neiderhiser, J., Hetherington, E. M., & Plomin, R. (2000). The Relationship Code:
Deciphering genetic and social patterns in adolescent development. Cambridge, MA:
Harvard University Press.
Robins, L. N., Cottler, L. B., Bucholz, K. K., Compton, W. M., North, C. S., & Rourke, K. M.
(2000). Diagnostic Interview Schedule for the DSM–IV (DIS–IV). St. Louis, MO:
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Psychological.
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This version of Table 1 is for reviewer use only. The formatted version of Table 1 follows.
Table 1. List of Study Measuresa
Measure
Adult Psychopathology and Drug Use
Composite International Diagnostic Instrument
CIDI Short Form: symptoms
Tobacco Use Frequency
Beck Anxiety Inventory
Beck Depression Inventory
Diagnostic Interview Schedule: antisocial personality &
conduct disorder
Personality Diagnostic Questionnaire
Elliott Social Behavior Questionnaire
Brief Depression/Anxiety Screeners
Police Contact
Family History Research Diagnostic Criteria
Birth Parent Report of the Other Birth Parent’s Mental
Health
Adoptive Parent Report of the Other Adoptive Parent’s
Mental Health
Adult Temperament, Personality, & Health
Temperament & Character Inventory
Adult Self-Perceived Competence
General Life Satisfaction Questionnaire
SF-36 Health
Optimism Scale
Adult Executive Functioning & Intelligence
Wechsler Adult Intelligence Scale: information &
picture completion
Computerized Stroop Task
Child Prenatal Exposure to Drugs
Pregnancy History Calendar
Medical Records
Parenting
HOME Inventory
Parenting Scale
Parent Daily Report
Parental Efficacy Questionnaire
Parenting Daily Hassles
Child Temperament
Infant Behavior Questionnaire
Toddler Behavior Questionnaire
Infant Characteristics Questionnaire
Maternal Perception Questionnaire
Home Temperament Task
Parent-Child Interaction
High Chair Task
Waiting Task
Mother-Father-Child Footprint Task
Mother-Child and Father-Child Free Play Task
Mother-Child and Father-Child Teaching Task
Mother-Child and Father-Child Clean Up Task
Reunion
Child Behavior and Health
Child Behavior Checklist
Preschool Socioaffective Profile
Sleep Habits
Your Child’s Health
Medical Records
3
B
B
B
B
B
B
6
Assessment (in child age months)
9
12
18
22
27
B
A
A
A,B
A,B
B
A
A
A
36
A
A
A
B
A,B
30
B
A,B
A,B
B
B
A
B
A
B
B
B
B
A
A
A
A
B
A,B
A,B
A
B
B
B
B
B
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
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Early Growth and Development Study
Child Executive Functioning & Language Development
Fruit and Animal Stroop Tasks
A
Inhibitory Control
A
A
Gift Delay Task
A
CBCL Language Scale
A
Potential Confounds/Instrumental Variables
Adoption Process Interview
B
A
Adoption Agency Experiences
B
A
Perceptions of Similarities and Differences
A
Adoption Profile
B
A
Opinions about Genetic Inheritance
B
A
Birth Parent Contact with Adoptive Parent
B
B
B
B
Adoptive Parent Contact with Birth Parent
A
A
A
A
A
A
A
B
A
A
Marital/Romantic Relationship Questionnaire
B
Marital Interaction Task
A
A
Negative Life Change Events
B
A
A,B
A
Family Financial Questionnaire
B
A
A,B
A
Demographics
B
A
A
A,B A,B
B
A
B
Note: A = adoptive family. B = birth parent. aFurther details on the measures are available from the author upon request.
21
A
A
Submitted to Twin Research and
Human Genetics—February 9, 2006
Early Growth and Development Study
22
Table 1. List of Study Measuresa
Assessment (in child age months)
Measure
3
6
9
12
18
22
27
Adult Psychopathology and Drug Use
Composite International Diagnostic Instrument
B
CIDI Short Form: symptoms
B
A
Tobacco Use Frequency
B
A
Beck Anxiety Inventory
B
A
A,B
A
Beck Depression Inventory
B
A
A,B
A
Diagnostic Interview Schedule: antisocial personality & conduct disorder
B
Personality Diagnostic Questionnaire
B
Elliott Social Behavior Questionnaire
B
A
A
B
Brief Depression/Anxiety Screeners
A,B
Police Contact
A,B
A,B
Family History Research Diagnostic Criteria
B
Birth Parent Report of the Other Birth Parent’s Mental Health
B
A
B
B
30
36
Submitted to Twin Research and
Human Genetics—February 9, 2006
Early Growth and Development Study
23
(Table 1 continued)
Adoptive Parent Report of the Other Adoptive Parent’s Mental Health
A
Adult Temperament, Personality, & Health
Temperament & Character Inventory
B
A
Adult Self-Perceived Competence
B
A
B
General Life Satisfaction Questionnaire
B
A
A,B
SF-36 Health
B
A
A,B
Optimism Scale
A
B
Adult Executive Functioning & Intelligence
Wechsler Adult Intelligence Scale: information & picture completion
B
Computerized Stroop Task
B
Child Prenatal Exposure to Drugs
Pregnancy History Calendar
B
Medical Records
B
Parenting
HOME Inventory
A
A
A
Submitted to Twin Research and
Human Genetics—February 9, 2006
Early Growth and Development Study
24
(Table 1 continued)
Parenting Scale
A
Parent Daily Report
A
A
A
A
A
A
Parental Efficacy Questionnaire
A
A
A
Parenting Daily Hassles
A
A
A
A
A
Child Temperament
Infant Behavior Questionnaire
A
Toddler Behavior Questionnaire
Infant Characteristics Questionnaire
A
A
A
Maternal Perception Questionnaire
A
A
A
Home Temperament Task
A
A
A
Parent-Child Interaction
High Chair Task
A
Waiting Task
A
Mother-Father-Child Footprint Task
A
Mother-Child and Father-Child Free Play Task
A
A
A
Submitted to Twin Research and
Human Genetics—February 9, 2006
Early Growth and Development Study
25
(Table 1 continued)
Mother-Child and Father-Child Teaching Task
A
Mother-Child and Father-Child Clean Up Task
Reunion
A
A
A
A
A
A
Child Behavior and Health
Child Behavior Checklist
A
Preschool Socioaffective Profile
A
A
Sleep Habits
A
A
A
Your Child’s Health
A
A
A
Medical Records
A
Child Executive Functioning & Language Development
Fruit and Animal Stroop Tasks
Inhibitory Control
A
A
A
Gift Delay Task
A
CBCL Language Scale
A
Potential Confounds/Instrumental Variables
Submitted to Twin Research and
Human Genetics—February 9, 2006
Early Growth and Development Study
26
(Table 1 continued)
Adoption Process Interview
B
Adoption Agency Experiences
B
A
A
Perceptions of Similarities and Differences
A
Adoption Profile
B
A
Opinions about Genetic Inheritance
B
A
Birth Parent Contact with Adoptive Parent
B
Adoptive Parent Contact with Birth Parent
Marital/Romantic Relationship Questionnaire
A
B
Marital Interaction Task
B
B
B
A
A
A
A
A
B
A
A
A
A
A
Negative Life Change Events
B
A
A,B
A
Family Financial Questionnaire
B
A
A,B
A
Demographics
B
A
A
A
A,B
A,B
B
A
Note: A = adoptive family. B = birth parent. aFurther details on the measures are available from the author upon request.
B
A
Submitted to Twin Research and
Human Genetics—February 9, 2006
Early Growth and Development Study
27
Table 2. Comparison Between Participants and Eligible Nonparticipants on Education, Income,
and Age
Participants
Nonparticipants
M (SD)
M (SD)
p
BM education
5.08 (3.14)
4.67 (3.08)
0.08
BM income
1.16 (0.43)
1.15 (0.49)
0.87
23.90 (6.01)
24.58 (6.39)
0.13
BF education
5.13 (3.25)
5.57 (3.72)
0.29
BF income
1.21 (0.41)
1.18 (0.44)
0.70
25.64 (7.43)
27.21 (8.19)
0.03
9.11 (1.92)
8.65 (2.46)
0.01
36.82 (5.59)
37.43 (5.86)
0.14
8.86 (2.31)
8.54 (2.58)
0.08
37.64 (5.64)
38.37 (6.39)
0.10
5.02 (1.18)
4.86 (1.27)
0.08
Variable
BM age
BF age
AM education
AM age
AF education
AF age
AP income
Note: BM = birth mother. BF = birth father. AM = adoptive mother. AF = adoptive father. AP =
adoptive parents. Education: 3 = completed 12th grade; 5 = completed trade school; 7 =
completed junior college; 9 = completed college. Income: 1 = $20,000 or less; 3 = $40,000–
59,999; 5 = $80,000–99,999.
Submitted to Twin Research and
Human Genetics—February 9, 2006
Early Growth and Development Study
Table 3. Self-Reported Level of Openness in the Adoption (Percentage of Participants)
Birth mother
Adoptive mother
Adoptive father
n = 276
n = 211
n = 205
Very closed
1%
0%
0%
Closed
4%
5%
7%
Mediated
10%
18%
17%
Semi-open
16%
17%
14%
Open
34%
38%
40%
Quite open
20%
13%
14%
Very open
16%
9%
8%
Level of openness
28
Submitted to Twin Research and
Human Genetics—February 9, 2006
Early Growth and Development Study
Figure Captions
Figure 1. GE correlation and GxE interaction on child pathology across development.
29
Birth
parent
pathology
Child
with difficult
temperament
Child
with behavior
problems
Child
pathology
Adoptive parent
with adverse
response
Adoptive parent
with very adverse
response
Adoptive parent
with noxious
response
Context: Adoptive parent psychopathology;
marital relations; economic stress