@article {431,
	title = {Parental age and offspring childhood mental health: A multi-cohort, population-based investigation},
	journal = {Child Development},
	volume = {91},
	year = {2020},
	pages = {964{\textendash}982},
	abstract = {<p>To examine the contributions of maternal and paternal age on offspring externalizing and internalizing problems, this study analyzed problem behaviors at age 10-12 years from four Dutch population-based cohorts (N = 32,892) by a multiple informant design. Bayesian evidence synthesis was used to combine results across cohorts with 50\% of the data analyzed for discovery and 50\% for confirmation. There was evidence of a robust negative linear relation between parental age and externalizing problems as reported by parents. In teacher-reports, this relation was largely explained by parental socio-economic status. Parental age had limited to no association with internalizing problems. Thus, in this large population-based study, either a beneficial or no effect of advanced parenthood on child problem behavior was observed.</p>
},
	doi = {10.1111/cdev.13267},
	author = {Zondervan-Zwijnenburg, Maria A J and Veldkamp, Sabine A M and Neumann, Alexander and Barzeva, Stefania A and Nelemans, Stefanie A and van Beijsterveldt, Catharina E M and Branje, Susan J T and Hillegers, Manon H J and Meeus, Wim H J and Tiemeier, Henning and Hoijtink, Herbert J A and Oldehinkel, Albertine J and Boomsma, Dorret I}
}
@article {418,
	title = {Genetic and environmental influences on different forms of bullying perpetration, bullying victimization, and their co-occurrence},
	journal = {Behavior Genetics},
	volume = {49},
	year = {2019},
	pages = {432{\textendash}443},
	abstract = {<p>Bullying comes in different forms, yet most previous genetically-sensitive studies have not distinguished between them. Given the serious consequences and the high prevalence of bullying, it is remarkable that the aetiology of bullying and its different forms has been under-researched. We present the first study to investigate the genetic architecture of bullying perpetration, bullying victimization, and their co-occurrence for verbal, physical and relational bullying. Primary-school teachers rated 8215 twin children on bullying perpetration and bullying victimization. For each form of bullying, we investigated, through genetic structural equation modelling, the genetic and environmental influences on being a bully, a victim or both. 34\% of the children were involved as bully, victim, or both. The correlation between being a bully and being a victim varied from 0.59 (relational) to 0.85 (physical). Heritability was \&nbsp; 70\% for perpetration and \&nbsp; 65\% for victimization, similar in girls and boys, yet both were somewhat lower for the relational form. Shared environmental influences were modest and more pronounced among girls. The correlation between being a bully and being a victim was explained mostly by genetic factors for verbal (\&nbsp; 71\%) and especially physical (\&nbsp; 77\%) and mostly by environmental factors for relational perpetration and victimization (\&nbsp; 60\%). Genes play a large role in explaining which children are at high risk of being a victim, bully, or both. For victimization this suggests an evocative gene-environment correlation: some children are at risk of being exposed to bullying, partly due to genetically influenced traits. So, genetic influences make some children more vulnerable to become a bully, victim or both.</p>
},
	keywords = {Bully-victims, Bullying, heritability, School, twins, Victimization},
	doi = {10.1007/s10519-019-09968-5},
	author = {Veldkamp, Sabine A M and Boomsma, Dorret I and de Zeeuw, Eveline L and van Beijsterveldt, Catharina E M and Bartels, Meike and Dolan, Conor V and van Bergen, Elsje}
}
