Birthweight-discordance and differences in early parenting relate to monozygotic twin differences in behaviour problems and academic achievement at age 7.

This longitudinal monozygotic (MZ) twin differences study explored associations between birthweight and early family environment and teacher-rated behaviour problems and academic achievement at age 7. MZ differences in anxiety, hyperactivity, conduct problems, peer problems and academic achievement correlated significantly with MZ differences in birthweight and early family environment, showing effect sizes of up to 2%. As predicted by earlier research, associations increased at the extremes of discordance, even in a longitudinal, cross-rater design, with effect sizes reaching as high as 12%. As with previous research some of these non-shared environmental (NSE) relationships appeared to operate partly as a function of SES, family chaos and maternal depression. Higher-risk families generally showed stronger negative associations.

[1]  Robert Plomin,et al.  Behavioral genetics in the postgenomic era , 2003 .

[2]  K. Thorpe.  A study of the use of the Edinburgh postnatal depression scale with parent groups outside the postpartum period , 1993 .

[3]  R. Plomin,et al.  Infant zygosity can be assigned by parental report questionnaire data , 2000, Twin Research.

[4]  E. Turkheimer,et al.  Nonshared environment: a theoretical, methodological, and quantitative review. , 2000, Psychological bulletin.

[5]  A. Rothenberger,et al.  Comparing the German Versions of the Strengths and Difficulties Questionnaire (SDQ-Deu) and the Child Behavior Checklist , 2000, European Child & Adolescent Psychiatry.

[6]  A. Carothers,et al.  The Validation of the Edinburgh Post-natal Depression Scale on a Community Sample , 1990, British Journal of Psychiatry.

[7]  R. Goodman.  The Strengths and Difficulties Questionnaire: a research note. , 1997, Journal of child psychology and psychiatry, and allied disciplines.

[8]  G. S. Pettit,et al.  Multiple risk factors in the development of externalizing behavior problems: Group and individual differences , 1998, Development and Psychopathology.

[9]  R. Plomin,et al.  Environmental risk and young children’s cognitive and behavioral development , 2006 .

[10]  R. Plomin,et al.  Twins Early Development Study (TEDS): A Multivariate, Longitudinal Genetic Investigation of Language, Cognition and Behavior Problems in Childhood , 2002, Twin Research.

[11]  R. Plomin,et al.  Why are Children in the Same Family So Different? Nonshared Environment a Decade Later , 2001, Canadian journal of psychiatry. Revue canadienne de psychiatrie.

[12]  R. Goodman,et al.  Psychometric properties of the strengths and difficulties questionnaire. , 2001, Journal of the American Academy of Child and Adolescent Psychiatry.

[13]  D. Reiss,et al.  Using MZ differences in the search for nonshared environmental effects. , 1996, Journal of child psychology and psychiatry, and allied disciplines.

[14]  R. Plomin,et al.  Nonshared environmental influences on individual differences in early behavioral development: a monozygotic twin differences study. , 2003, Child development.

[15]  R. Plomin,et al.  Why are children in the same family so different from one another? , 1987, Behavioral and Brain Sciences.

[16]  J. Cox,et al.  Detection of Postnatal Depression , 1987, British Journal of Psychiatry.

[17]  A. Matheny,et al.  Bringing order out of chaos: Psychometric characteristics of the confusion, hubbub, and order scale , 1995 .

[18]  K. Deater-Deckard,et al.  Parenting and child behavioral adjustment in early childhood: a quantitative genetic approach to studying family processes. , 2000, Child development.