For those not familiar with the English idiom, "a bee in her bonnet" means having a particular idea or complaint on her mind, an obsession, an idée fixe. Today on CBC1 I heard the All in the Mind program from October 9 on Parasites in Brains. http://www.abc.net.au/rn/allinthemind/
It was about various viruses, flukes, and such that spend at least part of their lives in the brains of their hosts, affecting their behaviour. In the case of people, apart from prions, about 30% of us are infected by Toxoplasma Gondii. This protozoan creature needs to have sex in cats. But cats excrete them. Then mice eat the feces. The Toxo gets into the brain of a mouse and makes it unafraid of cat urine. The mouse even likes the smell of cat urine. A cat eats the friendly mouse and, voilà, party-time for Toxo.
We like cats, and we handle cat feces and urine. Well, we try to avoid actually touching it, but we do keep litter boxes. Toxo gets into us, too. If you don't like cats, you may be exposed because Toxo is also in undercooked meat and in meat products (but we don't know which ones). In a small way, it causes us to be more neurotic: slightly more reactive, sort of dogmatic and rigid, and perhaps guilt-prone. It is doing this by affecting the immune system and dopamine centres. Apparently, this tends to make women smarter and men less so. Also the women become more warm-hearted and more interested in shopping. (I'm not making this up.)
You can't measure this "more" or "less" in a particular individual, but over large populations there is a noticeable effect about 30% of the variation among countries in neuroticism. The more neurotic cultures tend to have more rigid role-oriented societies. They tend to be more risk averse and prefer very unchanging political structures. They also tend to have strong gender definitions so that men do manly things and women do feminine things.
Toxo makes chemicls that might be used to help control certain psychoses like schizophrenia. On the other hand, it might be higher in people with Parkinson's disease.
Note to parents: pregnant women in the first trimester tend to be aversive to particular foods and to be disgusted by certain smells. So they don't want to clean the litter box. Good! Their aversion is protecting the growing baby.
Here's an idea from a reader of the website: Perhaps Toxo does make us more prone to like kitties. If we are attracted to lions, tigers and cougars, and who doesn't think they are beautiful, we might be eaten by those big cats, thereby fulfilling the reproductive imperative of little Toxo.