title: Genetic and environmental influences on religiousness: findings for retrospective and current religiousness ratings.
abstract: Estimates of the degree of genetic and environmental influences on religiousness have varied widely. This variation may, in part, be due to age differences in the samples under study. To investigate the heritability of religiousness and possible age changes in this estimate, both current and retrospective religiousness were assessed by self-report in a sample of adult male twins (169 MZ pairs and 104 DZ pairs, mean age of 33 years). Retrospective reports of religiousness showed little correlation difference between MZ (r=.69) and DZ (r=.59) twins. Reports of current religiousness, however, did show larger MZ (r=.62) than DZ (r=.42) similarity. Biometric analysis of the two religiousness ratings revealed that genetic factors were significantly weaker (12% vs. 44%) and shared environmental factors were significantly stronger (56% vs. 18%) in adolescence compared to adulthood. Analysis of internal and external religiousness subscales of the total score revealed similar results. These findings support the hypothesis that the heritability of religiousness increases from adolescence to adulthood.
authors.affiliation: Department of Psychology, University of Minnesota-Twin Cities, Minneapolis, MN 55455, USA. koen00999@umn.edu
authors.forename: Laura B
authors.initials: LB
authors.lastname: Koenig
authors.forename: Matt
authors.initials: M
authors.lastname: McGue
authors.forename: Robert F
authors.initials: RF
authors.lastname: Krueger
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Bouchard
mesh_terms: D000328:Adult; D006579:Heterozygote; D006720:Homozygote; D006801:Humans; D008297:Male; D012069:Religion and Psychology; D012189:Retrospective Studies; D012931:Social Environment; D014427:Twins / Q000235:genetics*