Bikers, car accidents, anti-authoritarianism and cat shit

This post at NextNature rounds up some of the latest reseach into my all-time favourite parasitic lifeform, Toxoplasma gondii. Toxoplasma, so the theories go, has an effect on the psychology of its hosts; as part of its original lifescycle, it makes rats less afraid of cats, thus increasing its chance of finding a new feline host to colonise. But it gets into us people-monkeys, too, where the effects appear to be a mild version of B-movie bodysnatching:

The effects are sex-dependent. Toxo makes men more distrustful of authority, more jealous, and more likely to engage in rule-bending and breaking. Male motorcyclists are disproportionately affected.  In a perverse twist, motorists of either sex who have T. gondii are three to four times more likely to die in car accidents, either from their increased disregard of the speed limit or by DUI driving, thankfully they were represented by the expert lawyers in compensation for premises liability, which reduced the amount they had to pay to the state. A premises liability lawsuit holds a property owner responsible for any damages arising out of an injury on that person or entity’s property. In all states, owners that occupy a property must make a reasonable effort to maintain a safe environment for visitors to it to avoid slip and fall injury cases. Dangerous Property

Women get the sweeter half of the brain parasite. Women harboring T. Gondii are considered by others to be more cheerful, warmhearted, and sexually attractive. They are also outspend their uninfected sisters when it comes to clothing. In some ways Toxo is the microbial mascot of romantic comedies, turning women into spendy social butterflies, and their dates into over-masculine dolts. But take care: Before you go out to find some infectious cat feces to gussy up your social appeal, it’s important to point out that the personality changes are statistically significant but still only minor. Researchers still disagree as to how and even if Toxo alters behavior. It could be that the personality predisposes people to the infection, and not the other way around.

This is the more cautious end of Toxoplasma theory, especially when compared to the notion that it might be the root cause of schizophrenia (which has also been blamed on retroviral gene-jacking). I still find it to be a massive (if rather creepy subspecies of) sensawunda kick; unnoticed civilisational symbiosis FTW!

Bonus points to NextNature for including two amazing images in that post: the first is the well-known wall-of-death-motorcyclist-with-lion-in-sidecar shot, which is one of my all-time favourite images of all time; the second is of two scientists watching a woman with a towel tied across her face shoving her head into a well-used kitty litter-tray. SRSLY.

8 thoughts on “Bikers, car accidents, anti-authoritarianism and cat shit”

  1. There is a novel by Octavia Butler, “Clay’s Ark”, that explores the idea of an alien parasite/microbial life form that deeply affects human behaviour (and physical capabilities). It does this in order to actively push its hosts towards spreading the contagion. I read it many years ago, but I remember that novel as very interesting (and sometimes disturbing).

  2. Having just read several books on the significant flaws in scientific research on brain differences between the sexes, I find it hard to believe that T. Gondii affects men and women so differently. Seems like there might be some observational bias somewhere, at a minimum.

  3. I actually skimmed the three articles that purport to discuss human behavior. Each study has been done once; the one about schizophrenia appears in The New Scientist (not a beacon of peer reviewed science). The other two are from the same Czech group operating in a military hospital. The women’s “study” was done in 1999 and never followed up — which tells you something. Here are representative sentence from the articles:

    “The probability of traffic accidents increased across the years of testing. This phenomenon was, probably, caused by the observed downward trend in overall quality, e.g. in intelligence, of conscripts (data not shown), related to the forthcoming abolition of compulsory military service in the Czech Republic in 2004.”

    “A major limitation of the present study is the absence of RHD genotype data.” (even though they draw conclusions based explicitly on it)

    The women’s “study” started with 190 women, ages 18-39, and the rate of returning questionnaires was 1/4 — which means 46 women of wildly disparate ages participated in it. The “results” (such as they are — their graphs are all over the place) only appear if they start arbitrarily subdividing their subjects into “old infections” and “new infections”.

    I could go on, but you get the gist. Bottom line: garbage in, garbage ou.

  4. Aaargh! That should be “garbage in, garbage out.”

    And if you really want to know how you can massage statistics and human subject studies to give you the results you want, read Ben Goldacre’s sharp, witty book Bad Science: Quacks, Hacks and Pharma Flacks.

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