Twin Families: When
Parental Conformity Relates to
Positive Child Outcomes
1K A Y L A
N. ANDERSON
1M A R T H A A . R U E T E R
2J E N N I F E R J . C O N N O R
1U
NIVERSITY OF MINNESOTA – TWIN CITIES
2S T . C L O U D S T A T E U N I V E R S I T Y
Why Twins?
 Twin rate: from 0.01 to 3.41% of all births (ASRM, 2012)
 Predominantly due to infertility treatment growth (like IVF)
 20 (Europe; ESHRE, 2014) to 30% (US; CDC, 2014) of IVF births = twins.

This is more than 20X the rate of twins in the general population
 Compared to singletons, twins’ early environments…
 …Aren’t good. This may be particularly true in IVF twin births.
60% of IVF twins premature; 53% low birth weight (SART, 2014)
 Relative to singletons, twin parents have higher rates of parenting
stress, anxiety & depression, and have poorer early parenting skills

(Olivennes et al., 2005; Thorpe et al., 2003; Vilksa & Unkila-Kallio, 2010; Holditch-Davis et al., 1999)
 (In singletons), these issues are related to worse child
psychosocial adjustment.
Why Twins?
 Head scratcher: Twins have better psychosocial
adjustment than singletons by middle childhood
(Anderson et al., 2014; Pulkkinen et al., 2003; Robbers et al., 2010; Moilanen et al., 1999).

Why is this? No one knows.
 Do twin family resources have different effects on
family (and indirectly child) outcomes relative to
singletons? (Anderson et al., 2014; Boss, 2002; McCubbin, 1979; Hill, 1958).
 In twin families, parents may have high expectations
for conformity to their rules to maintain order and
reduce household chaos (Garel et al., 1997; Jenkins & Coker, 2010).
This Study!
 Two goals:
 Do parental conformity expectations have different effects on
family outcomes, such as parent-child relationship
satisfaction, in twin and singleton families?
 Does the moderating effect of parental conformity
expectations by twin status indirectly explain differences in
twins’ and singletons’ psychosocial adjustment?
Study Participants
University of Minnesota Reproductive Medicine Center
Patient records (mother)
86% location, 82% participation rate
All IVF kids born between 1998-2004
198 families; 288 6 – 12 year old kids
126 twins (63 pairs); 162 singletons
Study Participants
IVF: High income, highly
educated, predominantly White
Kids: 54% female; M age = 8.47
28% Twin Birth Rate
Study Measures
Study Concept
Measurement
Twin Status
0 = Singleton; 1 = Twin
Parent-child Relationship Satisfaction
Adaptation of Huston MOQ
Relationship Measure (Huston & Vangelisti,
1991; Caughlin & Afifi, 2004)
Parental Conformity Expectations
Conformity subscale: Revised Family
Communication Patterns Questionnaire
(Ritchie & Fitzpatrick, 1990)
Child Psychosocial Adjustment
Child Behavior Checklist: Internalizing,
Externalizing, & Attention Problems
subscales (Achenbach & Rescorla, 2001)
Covariates: Parent emotional state (Adult Self Report Anxious Depressed Scale; Achenbach & Rescorla,
2003), age & education; child sex, age & prematurity status (1 = premature, 0 = not premature)
Statistical Model
P. Age
P. Emotional State
P. Education
Parent-child
Relationship
Satisfaction
Twin Status
Parental
Conformity
Expectations
C. Age
C. Sex
C.
Premature
Child
Adjustment
Indirect effects from the interaction
(twin status X conformity) & child
adjustment were modeled.
Child (Twin vs. Singleton) Emotional Problems
Parent-child
Relationship
Satisfaction
Twin Status
β=-0.35, p <.001
Emotional
Problems
β=0.16, p=0.015
Parental
Conformity
Expectations
Model Fit
c 2 =6.43, df = 6, p =0.38
SRMR = 0.01
CFI = 0.99
Dc2 = 1.14, df = 5, p > 0.05
TLI = 0.98
PC RS R2 =.14 (p=.017)
RMSEA = 0.02
EP R2 =.24 (p<.001)
Indirect effect interaction 
emotional adjustment:
β= -0.06, p = 0.027
Child (Twin vs. Singleton) Behavior Problems
Twin Status  Behavior Problems: β=-0.17, p <.001
Parent-child
Relationship
Satisfaction
Twin Status
β=-0.53, p <.001
Behavior
Problems
β=0.14, p=0.028
Parental
Conformity
Expectations
Model Fit
c 2 =3.56, df = 6, p =0.74
SRMR = 0.01
CFI = 1.00
Dc2 = 0.94, df = 5, p > 0.05
TLI = 1.07
PC RS R2 =.14 (p=.019)
RMSEA = 0.00
EP R2 =.39 (p<.001)
Indirect effect interaction 
behavioral adjustment:
β= -0.06, p = 0.027
Child (Twin vs. Singleton) Attention Problems
Twin Status  Attention Problems: β=-0.20, p <.001
Parent-child
Relationship
Satisfaction
Twin Status
β=-0.45, p <.001
Attention
Problems
β=0.15, p=0.020
Parental
Conformity
Expectations
Model Fit
c 2 =1.13 df = 6, p =0.98
SRMR = 0.00
CFI = 1.00
Dc2 = 0.67, df = 5, p > 0.05
TLI = 1.17
PC RS R2 =.13 (p=.019)
RMSEA = 0.00
EP R2 =.29 (p<.001)
Indirect effect interaction 
attention problems:
β= -0.07, p = 0.028
Parent-child Relationship Satisfaction
Twin Status*Parental Conformity Expectations
7
6.5
6
Low Parental Conformity Expectations
High Parental Conformity Expectations
5.5
Singletons
Twins
Low conformity: Twins had negative relationship with satisfaction, b
-0.19, p
=.013
High conformity: Twins have positive relationship with satisfaction, b = 2.71, p =.010
Conclusions & Future Directions
 Parental conformity expectations do have different
effects on family outcomes (parent-child relationship
satisfaction) in twin and singleton families.


What other family resources may have different effects?
What else of we know about singletons can’t be exactly applied
to twin populations?
 Different effects of conformity*twin status indirectly
(partially) explain twins’ more positive adjustment

What other factors explain twins’ more positive adjustment.
 How does this relate to what we know about early
cognitive development in twins? (twins worse; Olivennes et al., 2005;
Thorpe et al., 2003; Rutter et al., 2003)
Conclusions & Future Directions
 How might this be the same or different in twins
born without medical assistance?

What IVF specific factors should be examined that might be
different from general population twins?
 What might this look like in adolescence?
 When is it that the shift in adjustment occurs, and
when is it that family environments stop being
detrimental to twins and shift to being more helpful?

Parenting and relationship factors linked to poor twin and
parent outcomes in early childhood (Thorpe et al., 2003; Baor & Soskolne, 2012).
Contact & Acknowledgements
 Contact: Kayla Anderson, and02584@umn.edu
 Funding:
 Olson Marriage & Family Fellowship
 Minnesota Agricultural Experiment Station
 UMN Grant-in-Aid of Research
 UMN College of Education & Human Development Investment
Grant
References
Achenbach TM, Rescorla LA. Manual for the ASEBA school-age forms & profiles. 2001. University of
Vermont, Research Center for Children, Youth, & Families, Burlington, VT.
2.
Achenbach TM, Rescorla LA. Manual for the ASEBA Adult Forms & Profiles. 2003. University of Vermont,
Research Center for Children, Youth, & Families, Burlington, VT.
3.
Anderson KN, Koh BD, Connor JJ, Koerner AF, Damario M, Rueter MA. Twins conceived using assisted
reproduction: Parent mental health, family relationships, and child adjustment at middle childhood. Hum
Reprod 2014; 29: 2247-2255.
4.
Anderson KN, Rueter MA, Connor JJ (November, 2014). Families with Twins Developmental Stress Theory.
Presented at the National Council on Family Relations Theory Construction & Research Methodology
Workshop, Baltimore, MD.
5.
American Society for Reproductive Medicine. Multiple gestation associated with infertility therapy: an
American Society for Reproductive Medicine practice committee opinion. Fertil Steril. 2012; 97: 825-34.
6.
Baor L, Sosklone, V. Mothers of IVF twins: the mediating role of employment and social coping resources in
maternal stress. Women and Health. 2012: 52: 252-264.
7.
Boss P. Family Stress Management. 2002. Sage Publications, Thousand Oaks, CA.
8.
Caughlin JP, Afifi TD. When is topic avoidance unsatisfying? Examining moderators of the association
between avoidance and dissatisfaction. Human Communication Research. 2004; 30: 479-513.
9.
Centers for Disease Control. Assisted reproductive technology national summary report 2011.
http://www.cdc.gov/art/ART2011/NationalSummary_index.htm. Accessed July 25, 2014.
10. European Society for Human Reproduction and Embryology. ART fact sheet. www.eshre.eu/guidelines-andlegal/art-fact-sheet.aspx. Accessed September 18, 2014.
11. Garel M, Salobir C, Blondel B. (1997). Psychological consequences of having triplets: a 4-year follow-up study.
Fertil Steril 1997; 67: 1162-1165.
12. Hill R. Genetic features of families under stress. Social Casework. 1958; 49: 139-150.
1.
References
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
Holditch-Davis D, Roberts D, Sandelowski M. Early parental interactions with and perceptions of multiple birth
infants. J Adv Nurs. 1999; 30: 200-10.
Huston TL, Vangelisti AL. Socioemotional behavior and satisfaction in marital relationships. J Pers Soc Psychol
1991; 61: 721-733.
Jenkins DA, Coker R. Coping with triplets: perspectives from parents during the first four years. Health & Social
Work 2010; 35: 169-180.
McCubbin HI. Integrating coping behavior in family stress theory. J Marriage Fam 1979; 41: 237-244.
Moilanen I, Linna SL, Ebeling H, Kumpulaninen K, Tamminen T, Piha J, Almqvist F. Are twins’
behavioural/emotional problems different from singletons’? Eur Child Adoles Psy 1999; 8: 62-7.
Olivennes F, Golombok S, Ramogida C, Rust J, The Follow-Up Team. Behavioral and cognitive development as
well as family functioning of twins conceived by assisted reproduction: findings from a large population study.
Fertil Steril 2005; 84: 725-33.
Pulkkinen L, Vaalamo I, Hietala R, Kaprio J, Rose RJ. Peer reports of adaptive behavior in twins and singletons: is
twinship a risk or an advantage? Twin Research 2003; 6: 106-18.
Ritchie D, Fitzpatrick, MA. Family communication patterns: measuring intrapersonal perceptions of
interpersonal relationships. Communication Research 1990; 17: 523-544.
Robbers SCC, Bartels M, van Oort FVA, van Beijsterveldt CEM, van der Ende J, Verhulst FC, Boomsma DI,
Hulzink AC. A twin-singleton comparison of developmental trajectories of externalizing and internalizing
problems in 6-to 12-year-old children. Twin Research and Hum Genet 2010; 13: 79-87.
Society for Assisted Reproductive Technology. Multiple pregnancy. www.sart.org/Multiple_pregnancy_video/.
Accessed July 27. 2014.
Thorpe K, Rutter M, Greenwood R. Twins as a natural experiment to study the causes of mild language delay: II:
Family interaction risk factors. J Child Psychol Psyc 2003; 44: 342-55.
Vilska S, Unkila-Kallio L. Mental health of parents of twins conceived via assisted reproductive technology. Curr
Opin Obstet Gyn 2010; 22: 220-6.