Browsing by Subject "half-siblings"

Objective. Motives for childbearing are poorly understood, but it is well-renowned that fertility behavior runs in families. There is no agreement on mechanism of intergenerational fertility transmission. First in Finland, the aim of this study is to examine the relationship between the numbers of full and half-siblings (and maternal and paternal half-siblings) and fertility, and the association between half-siblings and timing of fertility. Since full and half-siblings differ in terms of relatedness and childhood backgrounds, it is possible to get better insights into mechanisms of fertility transmission, and better consider today’s heterogeneity in families. Methods. The current study utilized nationally representative registry data (FINNFAMILY). The sample (n = 35 063) consisted of women (49.1 %) and men in four birth cohorts (1955, 1960, 1965, 1970) which had completed fertility. Poisson regression analyses were used to examine relationships between the numbers of siblings (all siblings, full and half-siblings, maternal and paternal half-siblings) and children. Associations between half-siblings and fertility timing were examined by regressing the cumulative number of children over the participants’ reproductive age by the number of half-siblings. Results and discussion. The findings showed intergenerational fertility transmission in Finland. Half-siblings were differently associated with fertility between sexes. The number of half-siblings increased only women’s fertility, and women with half-siblings had higher completed fertility and earlier entry to parenthood. Maternal half-siblings were associated with women’s fertility, but not men’s. The findings support the idea of women as family kin keepers. Future research should further examine the role of sibling rivalry and mutual investments in fertility transmission.