title: Do non-shared environmental influences persist over time? An examination of days and minutes.
abstract: Non-shared environmental influences show only minimal stability over time prior to adulthood. The long assessment lags (typically 3-5 years) that characterize most longitudinal twin studies, however, make it difficult to interpret these results. To more rigorously evaluate non-shared environmental stability prior to adulthood, we fitted biometric correlated factors models to (1) seven consecutive days of self-reported negative and positive affect in 239 twin pairs aged 16-25 years and (2) seven consecutive minutes of observer rated warmth and control in 687 twin pairs aged 6-10 years. We then empirically examined patterns of etiologic stability over time using a mixed effects analog to the one-way ANOVA. Genetic and shared environmental correlations were found to be highly stable over both days and minutes. By contrast, non-shared environmental correlations decreased monotonically with increasing lag length, and moreover, were small-to moderate in magnitude when examining intervals longer than a few minutes. Such findings imply that the non-shared environment may be comprised primarily of transient and idiosyncratic effects prior to adulthood.
authors.affiliation: Department of Psychology, Michigan State University, 107D Psychology Building, East Lansing, MI, 48824, USA, burts@msu.edu.
authors.forename: S Alexandra
authors.initials: SA
authors.lastname: Burt
authors.forename: Ashlea M
authors.initials: AM
authors.lastname: Klahr
authors.forename: Kelly L
authors.initials: KL
authors.lastname: Klump
mesh_terms: D000293:Adolescent; D000328:Adult; D000339:Affect; D000704:Analysis of Variance; D002648:Child; D004644:Emotions; D004777:Environment; D005260:Female; D005824:Genetics, Behavioral; D006801:Humans; D007398:Interpersonal Relations; D016013:Likelihood Functions; D008137:Longitudinal Studies; D008297:Male; D008957:Models, Genetic; D015233:Models, Statistical; D009035:Mothers; D010641:Phenotype; D018401:Sample Size; D012931:Social Environment; D011795:Surveys and Questionnaires; D013997:Time Factors; D055815:Young Adult