Child-driven genetic factors can contribute to negative parenting and may increase the risk of being maltreated. Experiencing childhood maltreatment may be partly heritable, but results of twin... Show moreChild-driven genetic factors can contribute to negative parenting and may increase the risk of being maltreated. Experiencing childhood maltreatment may be partly heritable, but results of twin studies are mixed. In the current study, we used a cross-sectional extended family design to estimate genetic and environmental effects on experiencing child maltreatment. The sample consisted of 395 individuals (225 women; M-age = 38.85 years, range(age) = 7-88 years) from 63 families with two or three participating generations. Participants were oversampled for experienced maltreatment. Self-reported experienced child maltreatment was measured using a questionnaire assessing physical and emotional abuse, and physical and emotional neglect. All maltreatment phenotypes were partly heritable with percentages for h(2) ranging from 30% (SE = 13%) for neglect to 62% (SE = 19%) for severe physical abuse. Common environmental effects (c(2)) explained a statistically significant proportion of variance for all phenotypes except for the experience of severe physical abuse (c(2) = 9%, SE = 13%, p = .26). The genetic correlation between abuse and neglect was rho(g) = .73 (p = .02). Common environmental variance increased as socioeconomic status (SES) decreased (p = .05), but additive genetic and unique environmental variances were constant across different levels of SES. Show less
Child-driven genetic factors can contribute to negative parenting and may increase the risk of being maltreated. Experiencing childhood maltreatment may be partly heritable, but results of twin... Show moreChild-driven genetic factors can contribute to negative parenting and may increase the risk of being maltreated. Experiencing childhood maltreatment may be partly heritable, but results of twin studies are mixed. In the current study, we used a cross-sectional extended family design to estimate genetic and environmental effects on experiencing child maltreatment. The sample consisted of 395 individuals (225 women; M-age = 38.85 years, range(age) = 7-88 years) from 63 families with two or three participating generations. Participants were oversampled for experienced maltreatment. Self-reported experienced child maltreatment was measured using a questionnaire assessing physical and emotional abuse, and physical and emotional neglect. All maltreatment phenotypes were partly heritable with percentages for h(2) ranging from 30% (SE = 13%) for neglect to 62% (SE = 19%) for severe physical abuse. Common environmental effects (c(2)) explained a statistically significant proportion of variance for all phenotypes except for the experience of severe physical abuse (c(2) = 9%, SE = 13%, p = .26). The genetic correlation between abuse and neglect was rho(g) = .73 (p = .02). Common environmental variance increased as socioeconomic status (SES) decreased (p = .05), but additive genetic and unique environmental variances were constant across different levels of SES. Show less
Voorthuis, A.; Bakermans-Kranenburg, M.J.; IJzendoorn, M.H. van 2017
Several studies have shown that mothers and fathers have significant lower levels of testosterone (T) than non-mothers and non-fathers, and that in men caregiving is related to a decrease in T. To... Show moreSeveral studies have shown that mothers and fathers have significant lower levels of testosterone (T) than non-mothers and non-fathers, and that in men caregiving is related to a decrease in T. To date, only a few studies have examined T in women. We examined T reactivity to a crying infant simulator in 160 women. Use of oral contraceptives (OC), basal cortisol (CORT) levels and childhood experiences of maternal love withdrawal were taken into account. T levels were consistently significantly higher in women not using OC. In women not using OC, high basal CORT was related to higher initial T levels and larger decreases of T during caregiving. No effect of basal CORT was found in women with OC use. Childhood experiences of maternal love withdrawal did not affect T levels. This is the first study to show support for a decrease of T in women while taking care of a crying infant, supporting the Challenge hypothesis and the Steroid/Peptide Theory of Social Bonds. Show less
