"It's Okay, Everyone Else Is Doing It": Moral Disengagement and Peer Delinquency.

Fieder and Huber examined whether political leanings relate to fertility, potentially reflecting biological selection of political attitudes. Since political attitudes may have genetic bases, a fertility link could suggest selection pressures. Using the World Value Survey (WVS), they found a U-shaped pattern: individuals with strong left- or right-wing views had more children than moderates, though conservatives showed a stronger effect, suggesting balancing selection. In the European SHARE and the US GSS, however, only conservatives consistently had more children. At least in the US, this conservative advantage emerged after the 1990s; earlier, liberals also had relatively high fertility. This finding has been confirmed by Vogl and Freese, showing that larger families and individuals with more children tend to hold conservative views on family issues. As a result, population attitudes gradually shift toward the right. Fieder and Huber extended these findings with European data. Across Europe, conservatives had more children and grandchildren than liberals, echoing US patterns. These results suggest that the demographic transmission of conservative views—both socially and genetically—gradually shifts societies toward conservatism in Europe as well. Arpino and Mogi explored mechanisms behind this reproductive pattern, finding that extreme-right individuals were 4–5 percentage points more likely than centrists to intend having a child within three years. This effect persisted after controlling for religiosity, education, and income, and was strongest among younger (20–34), highly educated individuals, particularly in Eastern and Southern Europe. Similarly, Rackin and Gibson-Davis, analyzing US high school seniors (1989–2019), found Republicans consistently desired more children than Democrats, with the gap widening over time, while Neal and Neal showed that childfree adults in Michigan were more likely to be liberal. These findings intersect with broader demographic trends described by the Second Demographic Transition (SDT) framework, which links below-replacement fertility to cultural shifts such as individualization, secularization, and changing family norms. Subsequent work has emphasized how these shifts contribute to sustained low fertility across developed societies. Research further shows that while short-term economic downturns can depress fertility, the underlying SDT dynamics remains central to explaining long-term patterns of delayed childbearing and very low fertility. Together, this literature suggests that political fertility differentials operate within a broader demographic context in which below-replacement fertility has become the norm in much of the developed world.