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.
SGDP Centre, Institute of Psychiatry, King's College London, UK. spjgkaa@iop.kcl.ac.uk
Kathryn
K
Asbury
Judith F
JF
Dunn
Robert
R
Plomin
D001008:Anxiety Disorders; D001289:Attention Deficit Disorder with Hyperactivity; D001724:Birth Weight; D002648:Child; D002653:Child Behavior Disorders / Q000235:genetics*; D002675:Child, Preschool; D019955:Conduct Disorder; D004522:Educational Status; D004777:Environment; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D016487:Parenting; D010379:Peer Group; D012307:Risk Factors; D013334:Students; D014430:Twins, Monozygotic