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Biotech Science

Parasites Makes Us Dumber or Sexier 240

odie_q writes "It has long been known that the Toxoplasma gondii parasite alters its host's behavior, but now it seems the way it alters it depends on the sex of the host. From the article: 'A common parasite can increase a women's attractiveness to the opposite sex but also make men more stupid, an Australian researcher says ... Infected men have lower IQs, achieve a lower level of education and have shorter attention spans. They are also more likely to break rules and take risks, be more independent, more anti-social, suspicious, jealous and morose, and are deemed less attractive to women. On the other hand, infected women tend to be more outgoing, friendly, more promiscuous, and are considered more attractive to men compared with non-infected controls.'"
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Parasites Makes Us Dumber or Sexier

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  • by css-hack ( 1038154 ) on Saturday December 30, 2006 @04:57AM (#17407424)
    What are the odds that guys with low IQs, short attention spans, and an affinity for risks are just more likely to eat undercooked meat, and that the more outgoing promiscuous women catch it because of them.
  • Remember, kids! (Score:2, Insightful)

    by Guppy06 ( 410832 ) on Saturday December 30, 2006 @05:26AM (#17407494)
    Correlation != causation.

    Even since the last time this came up, I haven't seen anything done to differentiate between "symptoms of infection" and "traits of average cat owners."
  • by GrumpySimon ( 707671 ) <{zn.ten.nomis} {ta} {liame}> on Saturday December 30, 2006 @05:41AM (#17407540) Homepage
    I believe this is one of those news stories that sits around waiting for a slow news day. The original paper was released in November. It's written by Kevin Lafferty [] and was published in Proc. Roy. Soc. B [].

    It's a really quite fascinating paper - I recommend tracking it down if you can get access. Here's how it goes: Toxoplasmia gondii is adapated to live in cats and reproduces in felid intestinal cells & is shed, encysted, in their feaces. Then it can directly infect cats who come into contact with the cysts, or it encysts in brains of smaller mammals, and moves up the food chain as they get eaten until it hits a cat, and can reproduce again.

    Fascinatingly, T.g. appears to affect rodent behavior to increase predation risk - i.e. the rodents become more active, less fearful of cat/cat smells, and have increased dopamine levels (which supposedly leads to novelty seeking behavior and neuroticism-type behaviors, or at least, they do in humans).

    Despite humans not having any major cat predators, it could still affect us as a byproduct type of thing. Particularly that whole dopamine increase - this is should increase neuroticism levels.

    So - the big question - does prevalence of T.g. correlate with cultural variation in neuroticism in humans? Lafferty finds a fairly strong correlation ( r2 of 0.38 ) between population aggregate neuroticism (as measured by the fairly standard NEO PI-R [] personality inventory ).

    Unfortunately I think the populations he uses for his stats are a little bit suspect (always the problem with worldwide analyses though), but it's definitely worth a read. You should also keep in mind that so far it's only an interesting correlation and not a direct demonstration that T.g. causes large scale cultural differences.
  • by Anonymous Coward on Saturday December 30, 2006 @05:59AM (#17407586)
    Substitute Bush for Saddam, Bible for Koran, and Jesus for Mohammed and your post just might make sense.
  • by Nirvelli ( 851945 ) on Saturday December 30, 2006 @06:29AM (#17407678)
    I don't think it's just undercooked meat those people are eating:

    "A Toxoplasma infection occurs by:

    * Accidentally swallowing cat feces..."
  • Re:Remember, kids! (Score:3, Insightful)

    by khallow ( 566160 ) on Saturday December 30, 2006 @06:34AM (#17407686)

    Actually, I don't see why that particular effort would help. Obviously, being a cat owner would be a risk factor (assuming you were exposed to the cat's feces during the period when it is infectious, which is a few weeks after the cat is infected, so I gather). But so is gardening or exposure to rodents and other small animals. A better comparison would be of people who are infected with toxoplasma yet who aren't cat-owners. Being a cat owner involves a complex situation (eg, economic factors like living in a place where you can have a cat).

    Further, if we're going to pull out the correlation != causation thing, we should also consider Occam's razor. What's a simpler reason for behavior differences? Infection by a parasite that is already known to modify behavior *in the same way* in mammal species or some vague effect of cat ownership (especially given that the infected population includes a lot of people who don't own cats)?
  • by JKR ( 198165 ) on Saturday December 30, 2006 @07:21AM (#17407846)
    Lafferty finds a fairly strong correlation ( r2 of 0.38 ) ...

    Only in the social "sciences". Anywhere else, an r2 less than 0.95 is considered unimpressive, and 0.38 would definitely be "poor".
  • by Sique ( 173459 ) on Saturday December 30, 2006 @07:27AM (#17407878) Homepage
    "Never attribute to malice what can be explained by incompetence".

    I so hoped that George W. Bush would win the 2004 elections to make sure he is still president when the failure of his presidency becomes more clear. So no one can blame the ongoing breakdown in Iraq and the reappearing Taliban in Afghanistan to a liberal and weak Democrat administration which messes anything up the Bush Administration has started.

    I was starting to wonder if the strategies of the Bush administration might just be based on complete incompetence and ignorance after them closing in on Iraq in connection to 9/11. I had a teacher who was in Iraq on a development project in the 1970ies with still some connections there, and according to her Iraq had a mainly agnostic government based on arabic-nationalist and socialist ideas (e.g. arabic nationalsocialism). Tariq Aziz, the former second man in Iraq, is a maronite christian, not a muslim after all. So all alleged connections to a fundamentalist muslim group were doubtfull at best. Saddam Hussein was trying to play the muslim card after the fall of the Berlin Wall and the demise of the Soviet Union, because Socialism was no longer fashionable, but with the Gulf War in 1992 the Muslim Card also failed because all neighboring states (both baathist/fascist like Syria and fundamentally islamic as Saudi Arabia and the Gulf Sheikdoms) were telling him off.

    In the end Saddam Hussein seemed to me just a dictator which tried to cling on power with all means, and I guess he was completely unideologic except for the ideology that he was not to be toppled.

    A big hint to the complete misinterpretation of the situation in Iraq was to me that the development of the war was so different from the predictions. The South, which was considered pro-intervention and expected to greet the U.S. troups with flowers and celebration, was fighting hard, and the Sunni Triangle, which was suspected to be strongly defended and determined for a last stand, was taken within the matter of days. When the toppling of Saddam's statue in Bagdad was mainly watched with lethargy by the people (compare the video footage with that of the Berlin Wall in 1989!) and only a U.S. tank managed to pull it down finally I knew: The invasion was utterly botched, and the Iraqi population was at best waiting how it would work out in the end. The plundering and looting in the following weeks might have finally tilted the balance against the U.S., and at this very moment I was sure that the cause of "bringing democracy to the Arab world" was lost.

    It just took two hundred thousands dead Iraqis, the Abu Guraib scandal, the Guantanamo disaster and another three years of ongoing insurgence in Iraq to let the U.S. electorate figure out the same thing. And the Bush administration seems only to have changed course to avoid a complete election catastrophe in November 2006. So this movement seems not to be not based in a thinking process within the administation, but just a tactic maneuver to stay in power.
  • Re:George W. Bush (Score:2, Insightful)

    by Marcos Eliziario ( 969923 ) on Saturday December 30, 2006 @08:08AM (#17408014) Homepage Journal
    As I've said here before, the similarities between Brazil's president Lula and George Bush are astoundingly big.
    Both of them find out that there's a huge proportion of their electorates that are people who don't like to read, and are resentful of intelectuals. Both of them realized that this people constitute the majority of the people of their countries. And both of them discovered that the best way to capitalize those votes was to *act* just like that people. So, whenever they are in public or TV they *intentionally* mispell words, use stupid arguments like bad-taste analogies and from time to time make some comment about how intelectuals and scientists are not really that smart. The masses exultate with that, thinking that finally they have "someone just like ourselves" in the office.
    Curiously enough, both of them have a sinister, and very inteligent figure behind them. For Bush, it's Dick Cheney, for Lula, it's José Dirceu. Those figures serve the purpose of being the resident "evil" brains to take the blame when things go wrong. After all, they are portraited as over-intelligent figures, and for the dumb masses, this is always something kind of sinister.
    Lula become president of Brasil being the leader of the workers party. Most of the college professors and intelectuals where once members of that party, so if Lula always managed to keep his leadership it's not reasonable to think he is not very, very intelligent.
    The same can be said about George Bush. It's plain fuck stupid to think that someone dumb would get this far, and it's plain fuck stupid to believe that someone that came from Yale can't spell nuclear.
    They are acting, and their acting have being very succesful so far. Everytime someone calls them dumb, they win. Because this makes their target electorate even more affectionaly bound to them, and it helps to spread the lie that they can't be really responsible for their wrongs. Everytime a comedian makes a sophisticated joke about Bush's or Lula's supposed dumbness, he/she is only contributing to the myth of "someone just like us in charge". think about it.

  • by Paradigma11 ( 645246 ) <> on Saturday December 30, 2006 @10:07AM (#17408436)
    this is a field study, not an experiment!!!!!!!!!!!!!!!!!

    38% of the variance in the observered behaviour (answers in the fpi) is explained by the predictor variable.
    an r2 of 0.95 would mean, that the maximum correlation of another predictor could be 0.22 and you would have explained all human behaviour regarding the setting. think of zombie movies.

    that said, i am not a big fan of the neo-fpi. it is a questionaire which means it reports how people see themself or want other to see them. plus, it is based on classical test theory which has some major methodological issues and is outdated for more than half a century. this is something to critize the social "sciences" for, not an r2 of 0.38 :)
  • Re:FTA (Score:4, Insightful)

    by b0s0z0ku ( 752509 ) on Saturday December 30, 2006 @04:03PM (#17411162)
    It doesn't look to me as this is a terminal illness, the infection is gone in a few weeks to months, so it's hardly an explanation for the world's stupidity.

    It can be lethal if you have a weakened immune system due to age, chemo, HIV, whatever. BTW- it may persist as a low-grade infestation even in healthy people. The same as many other infections like syphilis, Lyme Disease, and even chickenpox - the initial symptoms of infection may go away but the pathogen stays in the body and causes mayhem a few years or even decades later.


  • Re:Remember, kids! (Score:2, Insightful)

    by poopdeville ( 841677 ) on Saturday December 30, 2006 @08:05PM (#17412520)
    The researchers have noted that toxoplasmosis secretes domanine-like molecules in mice. It has already been established that mice and humans share receptors for this molecule. It has already been established that dopamine levels affect human behaviour and mood. Mutatis mutandis, toxoplasmosis affects human behaviour and mood.

Would you people stop playing these stupid games?!?!?!!!!