Age-Related Differences in the Structure of Genetic and Environmental Contributions to Types of Peer Victimization

Abstract

Background: The goal of the present investigation was to clarify and compare the structure of genetic and environmental influences on different types (e.g., physical, verbal) of peer victimization experienced by youth in pre-/early adolescence and mid-/late adolescence. Method: Physical, verbal, social, and property-related peer victimization experiences were assessed in two twin samples (306 pairs, ages 9–14 and 294 pairs, ages 15–20). Cholesky decompositions of individual differences in victimization were conducted, and independent pathway (IP) and common pathway (CP) twin models were tested in each sample. Results: In the younger sample, a Cholesky decomposition best described the structure of genetic and environmental contributors to peer victimization, with no evidence that common additive genetic or environmental factors influence different types of peer victimization. In the older sample, common environmental factors influenced peer victimization types via a general latent liability for peer victimization (i.e., a CP model). Conclusions: Whereas the pre-/early adolescent sample demonstrated no evidence of a shared genetic and environmental structure for different types of peer victimization, the mid-/late adolescent sample demonstrates the emergence of an environmentally-driven latent liability for peer victimization across peer victimization types.

Heritability of Bullying and Victimization in Children and Adolescents: Moderation by the KiVa Antibullying Program

“…(42% and 70%, respectively) versus social/relational (0% and 55%) and property-related victimization (0%, only in Eastman et al, 2018). In addition, the twin studies also seem to differ, for example, with regards to informants used and age of participants.…”

“…However, these variations could be accounted for by a variety of reasons. For instance, both Eastman et al (2018) and Veldkamp et al (2019) found that heritability estimates vary depending on the type of victimization; they found higher heritabilities for physical Residual scores from which the effects of grade, gender, group status and pre-intervention level of bullying or victimization were removed. A = additive genetic effects, D = dominant genetic effects, E = non-shared environmental effects including error.…”

“…When multiple informants were used in a latent model of peer victimization and rejection, a significant and substantial contribution of genes was seen for twins from Kindergarten to grade 4 (H 2 = 73-94%; Boivin et al, 2013a), which is in line with our results. Eastman et al (2018) compared the genetic and environmental estimates derived from children (ages 9-14), versus adolescents (ages 15-20), and found differences in the magnitude and structure of genetic influences. The genetic contribution to victimization indicate that heritable characteristics in the child could evoke a negative reaction from peers and thus play a role in the likelihood of being bullied by others, a form of evocative rGE (Boivin et al, 2013a).…”

“…Such genetic influence on environmental exposure is called gene-environment correlation (rGE), and can be observed, for example, when an individual evokes a reaction (e.g., bullying) from the environment partly due to his or her genetic disposition for an underlying individual characteristic or behavior (Plomin, DeFries, & Loehlin, 1977). The heritability of peer victimization has been investigated in such a context, sometimes with mixed results, with heritability estimates ranging from 0-77% (Ball et al, 2008;Boivin et al, 2013a;Bowes et al, 2013;Brendgen et al, 2011Brendgen et al, , 2008Connolly & Beaver, 2016;Eastman et al, 2018;Shakoor et al, 2015;Silberg et al, 2016;Törn et al, 2015;Veldkamp et al, 2019). This variability across studies could be due to developmental differences having to do with the dynamic nature of peer relations/reputations and their assessments (see Boivin et al, 2013a).…”

“…Heritability estimates might also vary as a function of the type of victimization. For instance, victimization of physical bullying was found to have the highest heritability when compared to, for example, verbal or social/relational bullying (Eastman et al, 2018;Veldkamp et al, 2019). Some evidence of measured genetic risk factors for victimization was recently found through a multi-polygenic score approach (Schoeler et al, 2019).…”