title: Sleep and dream characteristics in twins.
abstract: A study of sleep and dream characteristics has been carried out by questionnaire on a sample of 77 MZ and 76 DZ same-sex twin pairs of two age groups, 6-8 and 16-18 years. Genetic effects could not be detected in the younger age group and appeared to be rather limited in the older one, possibly as a result of the limited variability of the considered variables and of the levelling influence of the common environment.
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D004325:Dreams; D005260:Female; D006801:Humans; D008297:Male; D011247:Pregnancy; D012890:Sleep; D013223:Statistics as Topic; D014427:Twins / Q000523:psychology; D014429:Twins, Dizygotic / Q000523:psychology; D014430:Twins, Monozygotic / Q000523:psychology