By the same authors

From the same journal

Clones in the Classroom: A Daily Diary Study of the Nonshared Environmental Relationship Between Monozygotic Twin Differences in School Experience and Achievement

Research output: Contribution to journalArticlepeer-review



Publication details

JournalTwin Research and Human Genetics
DatePublished - Dec 2008
Issue number6
Number of pages10
Pages (from-to)586-595
Original languageEnglish


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 (R-2 = 0.16, p < .01) and MZ differences in 'flow' in Science significantly predicted MZ differences in Science achievement (R-2 = 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.

Discover related content

Find related publications, people, projects, datasets and more using interactive charts.

View graph of relations