http://www.bbc.com/future/story/2013...g-enemy-within.
Check out this study:
http://rspb.royalsocietypublishing.o...1602/2749.full
Here are some of the symptoms, characteristic of conservative thinking, from the research:
In particular, humans with latent infections of the common protozoan parasite Toxoplasma gondii appear to experience a variety of long-term personality changes (Webster 2001). For instance, in infected women, intelligence, superego strength (rule-conscious, dutiful, conscientious, conforming, moralistic, staid and rule-bound) and affectothymia (warm, outgoing, attentive to others, kindly, easy-going, participating and likes people) are higher, while infected men have lower intelligence, superego strength and novelty-seeking (low novelty-seeking indicates rigid, loyal, stoic, slow-tempered and frugal personalities); both infected men and women have higher levels of guilt-proneness (they tend to be more apprehensive, self-doubting, worried, guilt prone, insecure, worrying and self-blaming