The world as I see it: genetic and environmental influences on primal world beliefs in a large Swedish twin sample

Beliefs about the general character of the world - called primals - have received much attention in recent years. Primals (e.g. believing that the world is safe) are associated with psychological and social outcomes, such as personality traits, character strengths and life satisfaction. We performed the first study of genetic and environmental influences on primals, and explored phenotypic associations between primals and the big five personality traits, in a large (similar to 9000) population-wide Swedish twin sample. Correlations between primals and personality traits were low to moderate. Broad-sense heritability estimates of primals ranged between 21% and 49%, suggesting that genetic factors contribute significantly to people's beliefs about the general character of the world. In contrast, we found little support for shared environmental effects (e.g. rearing environment). Conclusively, we demonstrate that primals and personality are related, yet distinct, constructs and that individual differences in primals depend on both genetic and non-shared environmental factors.