“Parent Contributions to the Development of Political Attitudes in Adoptive and Biological Families”, Emily A. Willoughby, Alexandros Giannelis, Steven Ludeke, Robert Klemmensen, Asbjørn S. Nørgaard, William Iacono, James J. Lee, Matt McGue2021-11-18 (, , ; similar)⁠:

Where do our political attitudes originate? Although early research attributed the formation of such beliefs to parent and peer socialization, genetically sensitive designs later clarified the substantial role of genes in the development of sociopolitical attitudes. However, it has remained unclear whether parental influence on offspring attitudes persists beyond adolescence.

In an unique sample of 394 adoptive and biological families with offspring more than 30 years old, biometric modeling revealed substantial evidence for genetic and nongenetic transmission from both parents for the majority of 7 political-attitude phenotypes. We found the largest genetic effects for religiousness and social liberalism, whereas the largest influence of parental environment was seen for political orientation and egalitarianism.

Together, these findings indicate that genes, environment, and the gene-environment correlation all contribute substantially to sociopolitical attitudes held in adulthood, and the etiology and development of those attitudes may be more important than ever in today’s rapidly changing sociopolitical landscape.

Figure 3: Proportion of variance in parent-offspring transmission attributable to parent genetics, parental environment, and parental gene-environment (G-E) covariance for each of the 7 political-attitude scales, their composite score, and the 16-item short form of the International Cognitive Ability Resource (ICAR-16; included as a negative control)