The personalities of Danish MPs: Trait- and aspect-level differences.

OBJECTIVE: We study personality traits of Danish parliamentarians (MPs) and examine elite-voter congruence and elite differentiation. Whereas previous political elite studies have focused only on the Big Five level, we include aspect-level differences. METHOD: In a highly representative survey of Danish MPs (N = 81; response rate = 46.3%) and a representative study of Danish voters (N = 3,612), we used the 60-item NEO-PI-R short version to examine personality differences on the Big Five level and, based on the NEO-BFAS, the aspect level. RESULTS: MPs were more extraverted, conscientious, and open than the average voter. On the elite level, liberal MPs were more agreeable and, on the aspect level, more compassionate but not more polite than conservative MPs. MPs in center parties had stronger power aspirations and were less agreeable and more extraverted than MPs in peripheral parties. On the aspect level, MPs in center parties were more assertive and enthusiastic and less polite. Conscientiousness and Agreeableness were associated with power aspiration, but Extraversion was not because the assertiveness effect was suppressed by a non-effect for enthusiasm. CONCLUSIONS: The inclusion of the aspect level explains null findings at the Big Five level and adds important nuances to the personality portrait of political elites.

Genetic influences on political ideologies: twin analyses of 19 measures of political ideologies from five democracies and genome-wide findings from three populations.

Almost 40 years ago, evidence from large studies of adult twins and their relatives suggested that between 30 and 60% of the variance in social and political attitudes could be explained by genetic influences. However, these findings have not been widely accepted or incorporated into the dominant paradigms that explain the etiology of political ideology. This has been attributed in part to measurement and sample limitations, as well the relative absence of molecular genetic studies. Here we present results from original analyses of a combined sample of over 12,000 twins pairs, ascertained from nine different studies conducted in five democracies, sampled over the course of four decades. We provide evidence that genetic factors play a role in the formation of political ideology, regardless of how ideology is measured, the era, or the population sampled. The only exception is a question that explicitly uses the phrase "Left-Right". We then present results from one of the first genome-wide association studies on political ideology using data from three samples: a 1990 Australian sample involving 6,894 individuals from 3,516 families; a 2008 Australian sample of 1,160 related individuals from 635 families and a 2010 Swedish sample involving 3,334 individuals from 2,607 families. No polymorphisms reached genome-wide significance in the meta-analysis. The combined evidence suggests that political ideology constitutes a fundamental aspect of one's genetically informed psychological disposition, but as Fisher proposed long ago, genetic influences on complex traits will be composed of thousands of markers of very small effects and it will require extremely large samples to have enough power in order to identify specific polymorphisms related to complex social traits.

The Danish political twin study: political traits in Danish twins and the general population.

We compare a recent Danish twin survey on political attitudes and behaviors to a nationally representative survey covering similar topics. We find very similar means and variances for most of our constructed scales of political attitudes and behaviors in the two surveys, although even small differences tend to be statistically significant due to sample size. This suggests that the twin study can be used to make inferences on the heritability of several political traits in the Danish population.