Behavior Genetics

, Volume 42, Issue 6, pp 875–885 | Cite as

Bigger Families Fare Better: A Novel Method to Estimate Rater Contrast Effects in Parental Ratings on ADHD Symptoms

  • R. Pinto
  • F. Rijsdijk
  • A. C. Frazier-Wood
  • P. Asherson
  • J. Kuntsi
Original Research


Many twin studies on parental ratings of attention deficit hyperactivity disorder (ADHD) symptoms report low or negative DZ correlations. The observed differences in MZ and DZ variances indicate sibling contrast effects, which appear to reflect a bias in parent ratings. Knowledge of the factors that contribute to this rater contrast effect is, however, limited. Using parent-rated ADHD symptoms from the Twins’ Early Development Study and a novel application of a twin model, we explored a range of socio-demographic variables (ethnicity, socio-economic status, and family size), as potential contributors to contrast effects and their interactive effect with gender composition of twin pairs. Gender did moderate contrast effects but only in DZ opposite-sex twin pairs. Family size also showed a moderating effect on rater contrast effects, which was further modified by gender. We further observed an effect of rating scale, with the DSM-IV ADHD subscale of the Revised Conners’ Parent Rating Scale more resistant to contrast effects than shorter scales of ADHD symptoms. The improved identification of situations where the accuracy of the most common informant of childhood ADHD symptoms—parents—is compromised as a result of rater bias, might have implications for future research on ADHD.


ADHD Twin study Contrast effects Rater bias 



We are indebted to participants of the Twins Early Development Study (TEDS) for making the study possible. The authors have no financial relationships to disclose. TEDS is funded by MRC Grant G0500079.

Supplementary material

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Supplementary material 1 (DOCX 14 kb)


  1. Burt SA (2009) Rethinking environmental contributions to child and adolescent psychopathology: a meta-analysis of shared environmental influences. Psychol Bull 135(4):608–637PubMedCrossRefGoogle Scholar
  2. Carey G (1986) Sibling imitation and contrast effects. Behav Genet 16(3):319–341PubMedCrossRefGoogle Scholar
  3. Conners CK, Sitarenios G, Parker JD, Epstein JN (1998) The revised Conners’ Parent Rating Scale (CPRS-R): factor structure, reliability, and criterion validity. J Abnorm Child Psychol 26(4):257–268PubMedCrossRefGoogle Scholar
  4. Faraone SV, Perlis RH, Doyle AE, Smoller JW, Goralnick JJ, Holmgren MA, Sklar P (2005) Molecular genetics of attention-deficit/hyperactivity disorder. Biol Psychiatry 57(11):1313–1323PubMedCrossRefGoogle Scholar
  5. Freitag CM, Rohde LA, Lempp T, Romanos M (2010) Phenotypic and measurement influences on heritability estimates in childhood ADHD. Eur Child Adolesc Psychiatry 19(3):311–323PubMedCrossRefGoogle Scholar
  6. Goodman R (1997) The Strengths and Difficulties Questionnaire: a research note. J Child Psychol Psychiatry 38(5):581–586PubMedCrossRefGoogle Scholar
  7. Greven CU, Rijsdijk FV, Plomin R (2011) A twin study of ADHD symptoms in early adolescence: hyperactivity-impulsivity and inattentiveness show substantial genetic overlap but also genetic specificity. J Abnorm Child Psychol 39(2):265–275PubMedCrossRefGoogle Scholar
  8. Hartman CA, Rhee SH, Willcutt EG, Pennington BF (2007) Modeling rater disagreement for ADHD: are parents or teachers biased? J Abnorm Child Psychol 35(4):536–542PubMedCrossRefGoogle Scholar
  9. Hay DA, Bennett KS, Levy F, Sergeant J, Swanson J (2007) A twin study of attention-deficit/hyperactivity disorder dimensions rated by the strengths and weaknesses of ADHD-symptoms and normal-behavior (SWAN) scale. Biol Psychiatry 61(5):700–705PubMedCrossRefGoogle Scholar
  10. Hogg C, Rutter M, Richman N (1997) Emotional and behavioral problems in children. NFER-Nelson, WindsorGoogle Scholar
  11. Hudziak JJ, Derks EM, Althoff RR, Copeland W, Boomsma DI (2005) The genetic and environmental contributions to oppositional defiant behavior: a multi-informant twin study. J Am Acad Child Adolesc Psychiatry 44(9):907–914PubMedCrossRefGoogle Scholar
  12. Kumarapeli P, Stepaniuk R, de Lusignan S, Williams R, Rowlands G (2006) Ethnicity recording in general practice computer systems. J Public Health (Oxf) 28(3):283–287CrossRefGoogle Scholar
  13. Kuntsi J, Eley TC, Taylor A, Hughes C, Asherson P, Caspi A, Moffitt TE (2004) Co-occurrence of ADHD and low IQ has genetic origins. Am J Med Genet B Neuropsychiatr Genet 124B(1):41–47PubMedCrossRefGoogle Scholar
  14. Kuntsi J, Rijsdijk F, Ronald A, Asherson P, Plomin R (2005) Genetic influences on the stability of attention-deficit/hyperactivity disorder symptoms from early to middle childhood. Biol Psychiatry 57(6):647–654PubMedCrossRefGoogle Scholar
  15. Martin N, Scourfield J, McGuffin P (2002) Observer effects and heritability of childhood attention-deficit hyperactivity disorder symptoms. Br J Psychiatry 180:260–265Google Scholar
  16. McLoughlin G, Ronald A, Kuntsi J, Asherson P, Plomin R (2007) Genetic support for the dual nature of attention deficit hyperactivity disorder: substantial genetic overlap between the inattentive and hyperactive-impulsive components. J Abnorm Child Psychol 35(6):999–1008PubMedCrossRefGoogle Scholar
  17. Merwood A, Greven CU, Price TS, Kuntsi J, McLoughlin G, Larsson H, Asherson P (submitted) Different heritabilities but shared aetiological influences for parent, teacher and self-ratings of ADHD symptoms: an adolescent twin study. Psychol MedGoogle Scholar
  18. Neale MC (1997) Mx. Department of Psychiatry, Medical College of Virginia, RichmondGoogle Scholar
  19. Pike A, Iervolino AC, Eley TC, Price TS, Plomin R (2006) Environmental risk and young children’s cognitive and behavioral development. Int J Behav Dev 30(1):55–66CrossRefGoogle Scholar
  20. Plomin R, DeFries JC, McClearn GE, McGuffin P (2008) Behavioral genetics. Worth Publishers, New YorkGoogle Scholar
  21. Polderman TJ, Derks EM, Hudziak JJ, Verhulst FC, Posthuma D, Boomsma DI (2007) Across the continuum of attention skills: a twin study of the SWAN ADHD rating scale. J Child Psychol Psychiatry 48(11):1080–1087PubMedCrossRefGoogle Scholar
  22. Price TS, Freeman B, Craig I, Petrill SA, Ebersole L, Plomin R (2000) Infant zygosity can be assigned by parental report questionnaire data. Twin Res 3(3):129–133PubMedGoogle Scholar
  23. Price TS, Simonoff E, Waldman I, Asherson P, Plomin R (2001) Hyperactivity in preschool children is highly heritable. J Am Acad Child Adolesc Psychiatry 40(12):1362–1364PubMedCrossRefGoogle Scholar
  24. Price TS, Simonoff E, Asherson P, Curran S, Kuntsi J, Waldman I, Plomin R (2005) Continuity and change in preschool ADHD symptoms: longitudinal genetic analysis with contrast effects. Behav Genet 35(2):121–132PubMedCrossRefGoogle Scholar
  25. Rietveld MJ, Hudziak JJ, Bartels M, van Beijsterveldt CE, Boomsma DI (2003a) Heritability of attention problems in children: I. cross-sectional results from a study of twins, age 3–12 years. Am J Med Genet B Neuropsychiatr Genet 117B(1):102–113PubMedCrossRefGoogle Scholar
  26. Rietveld MJ, Posthuma D, Dolan CV, Boomsma DI (2003b) ADHD: sibling interaction or dominance: an evaluation of statistical power. Behav Genet 33(3):247–255PubMedCrossRefGoogle Scholar
  27. Saudino KJ, Cherny SS, Plomin R (2000) Parent ratings of temperament in twins: explaining the ‘too low’ DZ correlations. Twin Res 3(4):224–233PubMedGoogle Scholar
  28. Saudino KJ, Wertz AE, Gagne JR, Chawla S (2004) Night and day: are siblings as different in temperament as parents say they are? J Pers Soc Psychol 87(5):698–706PubMedCrossRefGoogle Scholar
  29. Saudino KJ, Ronald A, Plomin R (2005) The etiology of behavior problems in 7-year-old twins: substantial genetic influence and negligible shared environmental influence for parent ratings and ratings by same and different teachers. J Abnorm Child Psychol 33(1):113–130PubMedCrossRefGoogle Scholar
  30. Sherman DK, McGue MK, Iacono WG (1997) Twin concordance for attention deficit hyperactivity disorder: a comparison of teachers’ and mothers’ reports. Am J Psychiatry 154(4):532–535PubMedGoogle Scholar
  31. Simonoff E, Pickles A, Hervas A, Silberg JL, Rutter M, Eaves L (1998) Genetic influences on childhood hyperactivity: contrast effects imply parental rating bias, not sibling interaction. Psychol Med 28(4):825–837PubMedCrossRefGoogle Scholar
  32. StataCorporation (1997) Stata statistical software. College Station, Stata CorporationGoogle Scholar
  33. Swanson JM, Schuck S, Mann M, Carlson C, Hartman K, Sergeant JA, Clevinger W, Wasdell M, McCleary R (2006) Categorical and dimensional definitions and evaluations of symptoms of ADHD: the SNAP and SWAN Rating Scales. Retrieved December 2010 from http://wwwADHDnet
  34. Thapar A, Harrington R, Ross K, McGuffin P (2000) Does the definition of ADHD affect heritability? J Am Acad Child Adolesc Psychiatry 39(12):1528–1536PubMedCrossRefGoogle Scholar
  35. Trouton A, Spinath FM, Plomin R (2002) Twins early development study (TEDS): a multivariate, longitudinal genetic investigation of language, cognition and behavior problems in childhood. Twin Res 5(5):444–448PubMedGoogle Scholar
  36. van Beijsterveldt CE, Verhulst FC, Molenaar PC, Boomsma DI (2004) The genetic basis of problem behavior in 5-year-old dutch twin pairs. Behav Genet 34(3):229–242PubMedCrossRefGoogle Scholar
  37. Vierikko E, Pulkkinen L, Kaprio J, Rose RJ (2004) Genetic and environmental influences on the relationship between aggression and hyperactivity-impulsivity as rated by teachers and parents. Twin Res 7(3):261–274PubMedGoogle Scholar
  38. Wood AC, Buitelaar J, Rijsdijk F, Asherson P (2009) Kuntsi J (2010) Rethinking shared environment as a source of variance underlying attention-deficit/hyperactivity disorder symptoms: comment on Burt. Psychol Bull 136(3):331–340CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC 2012

Authors and Affiliations

  • R. Pinto
    • 1
  • F. Rijsdijk
    • 1
  • A. C. Frazier-Wood
    • 1
    • 2
  • P. Asherson
    • 1
  • J. Kuntsi
    • 1
  1. 1.King’s College London, MRC Social, Genetic and Developmental Psychiatry Centre, Institute of PsychiatryLondonUK
  2. 2.Division of Epidemiology, Human Genetics and Environmental SciencesThe University of Texas School of Public HealthHoustonUSA

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