Results of the study: Hirsh, JB et al:

Compassionate liberals and political conservatives: associations of agreeableness with political ideology and moral values. Pers Soc Psychol Bull 2010 May;36(5):655 – 64

In the study "Compassionate liberals and polite conservatives: associations of agreeableness with political ideology and moral values", Hirsh and his colleagues examined the connection between personality traits, political ideology and moral values.

They found that people with higher agreeableness were more likely to support liberal political views and value moral values such as caring and compassion. In contrast, individuals with low agreeableness tended to hold conservative political views and valued moral values associated with authority and purity.

The results suggest that personality traits such as agreeableness may play an important role in which political views and moral values people prefer.