title: Clones in the classroom: a daily diary study of the nonshared environmental relationship between monozygotic twin differences in school experience and achievement.
abstract: Do genetically identical children experience the same classroom differently? Are nonshared classroom experiences associated with differences in achievement? We designed a telephone diary measure which we administered every school day for 2 weeks to 122 10-year-olds in 61 monozygotic (MZ) twin pairs. Each pair shared genes, a classroom, peers and a teacher. We found that MZ twins did experience their classrooms differently (rMZ < 0.65 for all measures of classroom experience). Furthermore, MZ differences in peer problems were significantly associated with MZ differences in Mathematics achievement (ES = 8%); differences in positivity about school were significantly associated with differences in Mathematics (ES = 15%) and Science (ES = 8%) achievement; and differences in 'flow' in Science lessons were associated with differences in Science achievement (ES = 12%). In a multiple regression analysis, MZ differences in positivity about school significantly predicted MZ differences in Mathematics achievement (R2 = 0.16, p < .01) and MZ differences in 'flow' in Science significantly predicted MZ differences in Science achievement (R2 = 0.10, p < .05). These results indicate that MZ twins experience the classroom differently and that differences in their experience are associated with differences in their achievement.
authors.affiliation: Social, Genetic and Developmental Psychiatry Centre, King's College London, United Kingdom. k.asbury@iop.kcl.ac.uk
authors.forename: Kathryn
authors.initials: K
authors.lastname: Asbury
authors.forename: David
authors.initials: D
authors.lastname: Almeida
authors.forename: Jacob
authors.initials: J
authors.lastname: Hibel
authors.forename: Nicole
authors.initials: N
authors.lastname: Harlaar
authors.forename: Robert
authors.initials: R
authors.lastname: Plomin
mesh_terms: D002648:Child; D032882:Comprehension; D004522:Educational Status; D005260:Female; D006801:Humans; D008297:Male; D008433:Mathematics; D011340:Problem Solving; D012574:Schools; D014430:Twins, Monozygotic