In the first stage of our analysis, we demonstrated that there are several substantively significant relationships between the personality traits and political ideology dimensions. Most notably, P [a complex variable, but derived from “Psychoticism”] is substantially correlated with conservative military and social attitudes, while Social Desirability is related to liberal social attitudes, and Neuroticism is related to liberal economic attitudes [emphasis added by TC]. Our findings at the phenotypic level are highly consistent with similar explorations in an Australian population (Verhulst, Hatemi, and Martin 2010).
The results are generated from twins data. I found this discussion very interesting, as it shows the standard personality-to-politics chain is only part of a richer story:
These findings directly challenge the causal pathway assumed in the extant literature (e.g., Gerber et al. 2010; Mondak et al. 2010). Rather than personality traits causing people to develop liberal or conservative political attitudes, the current results suggest two alternative relationships. First, the combined Cholesky and DoC analyses suggest that a common set of genes mutually influences personality traits and political attitudes, implying the relationship between personality and politics is a function of an innate common genetic factor rather than a sequential personality to politics model (see the right panel of Figure 1). The results from the DoC analysis also suggest an alternative causal model. That is, the latent set of genes shared between political attitudes and personality traits directly influences attitudes and indirectly influences personality traits. In other words, the genetic component of political attitudes partially mediates the genetic influence on personality traits. This finding is completely opposite from the basic assumption in the most recent literature (e.g., Gerber et al. 2010; Mondak et al. 2010). Thus, it appears the genetic component of political attitudes measured relatively later in an individual’s life contributes to the development of an individual’s personality along the way. In this view, attitudes are more than what is expressed in adulthood, but part of one’s disposition which guides behavior and selection into environments, which later are recognized and measured as attitudes in adulthood. Regardless of whether the final analysis supports a latent genetic source of covariance or a mutual causal structure, both perspectives require a major revision to the prevailing assumptions about political attitudes and personality traits.
That is from Verhulst, Eaves, and Hatemi.