title: Co-rumination cultivates anxiety: a genetically informed study of friend influence during early adolescence.
abstract: This study tested 2 related hypotheses. The first holds that high co-rumination anticipates heightened internalizing problems. The second holds that positive relationships with friends exacerbate the risk for internalizing problems arising from co-rumination. A sample of MZ twins followed from birth (194 girls and 170 boys) completed (a) self-reports of friendship support, friendship negativity, and co-rumination with friends at age 12 and (b) measures of anxiety and depression at ages 12 and 13. Using a monozygotic twins-difference design, within-pair differences in co-rumination predicted increased within-pair differences in anxiety (but not depression), after removing the covariance between co-rumination and perceptions of friendship. In other words, the difference in co-rumination within each monozygotic twin pair predicted an increase in the difference in their anxiety levels, but not the difference in their depression levels. The discussion focuses on nonshared environmental influences, because the monozygotic twin-difference design eliminates the possibility that associations were driven by heritability or by shared environmental factors that underlie friendship experiences and internalizing problems.
authors: Department of Psychology, Florida Atlantic University.
authors: Shrija
authors: S
authors: Dirghangi
authors: Department of Psychology, Florida Atlantic University.
authors: Gilly
authors: G
authors: Kahn
authors: Department of Psychology, Florida Atlantic University.
authors: Brett
authors: B
authors: Laursen
authors: Department of Psychology, University of Quebec in Montreal.
authors: Mara
authors: M
authors: Brendgen
authors: Department of Psychoeducation, University of Montreal.
authors: Frank
authors: F
authors: Vitaro
authors: School of Psychology, Laval University.
authors: Ginette
authors: G
authors: Dionne
authors: School of Psychology, Laval University.
authors: Michel
authors: M
authors: Boivin
mesh_terms: D000293:Adolescent; D000294:Adolescent Behavior / Q000523:psychology; D001007:Anxiety / Q000523:psychology*; D002648:Child; D005260:Female; D033062:Friends / Q000523:psychology*; D006801:Humans; D007398:Interpersonal Relations; D008297:Male; D012650:Self Disclosure; D011795:Surveys and Questionnaires; D014430:Twins, Monozygotic