@article{discovery10059578,
            note = {This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted re-use, distribution, and reproduction in any medium, provided the original work is properly cited.},
            year = {2018},
           title = {Aggressive behaviour in childhood and adolescence: the role of smoking during pregnancy, evidence from four twin cohorts in the EU-ACTION consortium},
         journal = {Psychological Medicine},
            issn = {1469-8978},
          author = {Malanchini, M and Smith-Woolley, E and Ayorech, Z and Rimfeld, K and Krapohl, E and Vuoksimaa, E and Korhonen, T and Bartels, M and van Beijsterveldt, TCEM and Rose, RJ and Lundstr{\"o}m, S and Anckars{\"a}ter, H and Kaprio, J and Lichtenstein, P and Boomsma, DI and Plomin, R},
             url = {https://doi.org/10.1017/S0033291718001344},
        abstract = {BACKGROUND:
Maternal smoking during pregnancy (MSDP) has been linked to offspring's externalizing problems. It has been argued that socio-demographic factors (e.g. maternal age and education), co-occurring environmental risk factors, or pleiotropic genetic effects may account for the association between MSDP and later outcomes. This study provides a comprehensive investigation of the association between MSDP and a single harmonized component of externalizing: aggressive behaviour, measured throughout childhood and adolescence.

METHODS:
Data came from four prospective twin cohorts - Twins Early Development Study, Netherlands Twin Register, Childhood and Adolescent Twin Study of Sweden, and FinnTwin12 study - who collaborate in the EU-ACTION consortium. Data from 30 708 unrelated individuals were analysed. Based on item level data, a harmonized measure of aggression was created at ages 9-10; 12; 14-15 and 16-18.

RESULTS:
MSDP predicted aggression in childhood and adolescence. A meta-analysis across the four samples found the independent effect of MSDP to be 0.4\% (r = 0.066), this remained consistent when analyses were performed separately by sex. All other perinatal factors combined explained 1.1\% of the variance in aggression across all ages and samples (r = 0.112). Paternal smoking and aggressive parenting strategies did not account for the MSDP-aggression association, consistent with the hypothesis of a small direct link between MSDP and aggression.

CONCLUSION: 
Perinatal factors, including MSDP, account for a small portion of the variance in aggression in childhood and adolescence. Later experiences may play a greater role in shaping adolescents' aggressive behaviour.}
}