10.6084/m9.figshare.8167457.v1 Peter Lenart Peter Lenart Filip Zlámal Filip Zlámal Lubomír Kukla Lubomír Kukla Jiří Jarkovský Jiří Jarkovský Julie Bienertová-Vašků Julie Bienertová-Vašků Models 4 and 5: all variables from Sibling relatedness rather than father absence predicts earlier age at menarche in ELSPAC cohort The Royal Society 2019 menarche sibling relatedness father absence inclusive fitness ELSPAC 2019-05-22 11:40:18 Dataset https://rs.figshare.com/articles/dataset/Models_4_and_5_all_variables_from_Sibling_relatedness_rather_than_father_absence_predicts_earlier_age_at_menarche_in_ELSPAC_cohort/8167457 Many studies during the past 50 years have found an association between father absence and earlier menarche. In connection with these findings, several evolutionary theories assume that father absence is a causal factor accelerating reproductive development. However, a recent study analysing data from the Avon Longitudinal Study of Parents and Children (ALSPAC) found that father absence does not predict age at menarche when adjusted for sibling relatedness. In this study, we have replicated these results in the Czech section of the European Longitudinal Study of Pregnancy and Childhood (ELSPAC), which used the same questionnaires as ALSPAC to study a geographically distinct population. Our results support the conclusion that sibling relatedness rather than father absence predicts age at menarche. Furthermore, our results show that age at menarche in 1990s UK and Czech cohorts is very similar despite socioeconomic differences between the two countries.