Join 3,558 readers in helping fund MetaFilter (Hide)


The Return of the Puppet Masters
January 21, 2006 11:00 AM   Subscribe

Are brain parasites altering the personalities of three billion people?
posted by moonbird (56 comments total)

 
See also.
posted by Gyan at 11:06 AM on January 21, 2006


Apparently yes. Shocking stuff.
posted by mokey at 11:10 AM on January 21, 2006


Speedy find, Gyan. I recommend Ortho's post as it has a lot of excellent linkage (hadn't seen it first time 'round).
posted by moonbird at 11:12 AM on January 21, 2006


Yes. No.
posted by weapons-grade pandemonium at 11:12 AM on January 21, 2006


cats own us ... that is all
posted by pyramid termite at 11:12 AM on January 21, 2006


I for one welcome our new parasitic feline overlords.
posted by crunchland at 11:16 AM on January 21, 2006


This manipulation likely evolved through natural selection, since parasites that were more likely to end up in cats would leave more offpsring.

That's what the cat-loving liberal media wants us to think. Of course, the parasite was in fact intelligently designed ... by evil cat geneticists in their hidden mountain lair!
posted by IshmaelGraves at 11:19 AM on January 21, 2006


Is this the cat thing again?
posted by jenovus at 11:20 AM on January 21, 2006


It's estimated that about half of all people on Earth are infected with Toxoplasma. ... Parasitologist Jaroslav Flegr of Charles University in Prague administered psychological questionnaires to people infected with Toxoplasma and controls. Those infected, he found, show a small, but statistically significant, tendency to be more self-reproaching and insecure. Paradoxically, infected women, on average, tend to be more outgoing and warmhearted than controls, while infected men tend to be more jealous and suspicious.

First rule of psychological experimentation: Correlation does not imply causation. If all he's got is some surveys to back it up, I'm not buying that it's the Toxoplasma making the difference. Now if he's infecting people and then questioning them before and after, that I might buy. But I doubt he could get it by the University ethicists. The rat experiment seems pretty solid though. Why is it that articles like this never explain their human sample populations very well, if at all?
posted by Roger Dodger at 11:23 AM on January 21, 2006


Hmmm, so that's why lately I have this intense desire to stick a coat hanger in my ear and Scrape Off The Inside OF MY FUCKING SKULL!!!!
posted by Turtles all the way down at 11:29 AM on January 21, 2006


Of course, the good news is that there's a simple toxoplasmosis test. If you can get your blood drawn, you can find out if you're sekritly being controlled by cats.
posted by booksandlibretti at 11:32 AM on January 21, 2006


Roger Dodger, while I somewhat agree with you, you should read the previous post (linked in the first comment) links. Also, one must remember mammal brains are exceptionally alike, so it is not very far off to propose human hosts would have their behavior modified. Obviously it is not very efficient (from the microorganism point of view) to try to have humans eaten by cats, but eventually natural selection may develop the bug so that it will make people like cats, for instance.
posted by nkyad at 11:34 AM on January 21, 2006


Does this have anything to do with Resident Evil 4? Because I got that game for Christmas, and it's hella rad.
posted by bardic at 11:34 AM on January 21, 2006


Walk around not wearin' a hat!
posted by WolfDaddy at 11:36 AM on January 21, 2006


Yeah, there's definitely an alternative hypothesis to the idea that the parasite is causing changes in human behavior. If, say, people who own cats are more likely to be infected with the parasite, then the differences between the two samples might have something to do with pet ownership rather than infestation. After all, haven't we all heard of the studies that show that owning a pet changes quality of life?

None of that changes my immediate desire to spray massive amounts of pesticides into my ears, however.
posted by Chanther at 11:47 AM on January 21, 2006


Also from the BBC: Scientists warn that the parasitical disease toxoplasmosis could increase the risk of having a road accident.
posted by John Shaft at 11:47 AM on January 21, 2006


The correlation/causality thing was the first bit I thought of. It's quite possible that the things that most often expose you to toxoplasmosis are the result of activities more often participated in by the withdrawn/reproachful.

Example: If such a person is more likely to buy a cat than a dog (and it's not much of a stretch to declare this), and cats drastically increase your likelihood of infection, you'd see an obvious correlation between behavior and infection that doesn't necessarily mean the infection caused the behavior.
posted by dougunderscorenelso at 12:04 PM on January 21, 2006


cats own us ... that is all

We needed scientific tests to tell us this?
posted by arcticwoman at 12:06 PM on January 21, 2006


Would you prefer to accept it on faith?
posted by mischief at 12:12 PM on January 21, 2006


I do not need science or faith to tell me that. I am informed of its truth by my dread master. I will go buy more tuna now.
posted by hattifattener at 12:15 PM on January 21, 2006


Tell me when they find the parasite that makes people smarter.
posted by TwelveTwo at 12:23 PM on January 21, 2006


Is there a urine or blood test for toxoplasmosis?
posted by Kickstart70 at 12:51 PM on January 21, 2006


Does this have anything to do with Resident Evil 4? Because I got that game for Christmas, and it's hella rad.

A little, in one of Luis' memos, he writes of three parasites that control their hosts to some degree, Dicrocoelium (as mentioned in the article), Galactosomum (his description sounds like Euhaplorchis californiensis in the article) and Leucochlordium (some sort of snail parasite).
posted by bobo123 at 12:58 PM on January 21, 2006


If this is true, then what of other parasites we have yet to detect. Could most personality traits simply be a collection of what active parasites you have?
posted by skallas at 12:59 PM on January 21, 2006


Yes, Kickstart70, as I commented above, there's a simple blood test if you are that paranoid. Even if you missed it, you know, Google is your friend.
posted by booksandlibretti at 1:04 PM on January 21, 2006


Seems to me that, since those with toxoplasma have week immune systems, the difference in behavior is linked to having to be extra careful about hygene and such. But I'd like to think the scientists accounted for that, and they probably did.
posted by Citizen Premier at 1:07 PM on January 21, 2006


I just found a college paper I wrote on behavior modifying parasites, which has some relevant references in it. If you have access to scholarly databases, they might be worth looking up. These two are studies like the one the moonbird linked to, showing study design, size of changes and possible alternate hypotheses.

*Flegr, Jaroslav, Petr Kodym and Vera Tolarova. “Correlation of Duration of Latent Toxoplasma gondii Infection with Personality Changes in Women.” Biological Psychology. 53
(2000) 57-68.

*Flegr, Jaroslav, Mareek Preiss, Jiri Klose, Jan Havlicek, Martina Vitakova, and Petr Kodym.
“Decreased Level of Psychobiological Factor Novelty Seeking and Lower Intelligence in Men Latently Infected with the Protozoan Parasite Toxoplasma gondii Dopamine, a Missing Link between Schizophrenia and Toxoplasmosis?” Biological Psychology. 63 (2000) 253-268.

This last one is more interesting. So, first off, most of these parasites can travel through multiple hosts during their lives, one of which is "better". For example, toxoplasma gondii cycles mainly between rats and cats. Most scientists argue that the parasite changes behavior in the prey host to make them more vulnerable to the predator the parasite prefers. There is another theory that in some cases it is better for the prey animal to "commit suicide" in order to increase family fitness. (group fitness is a controversial area of evolution)

*Smith Trail, Deborah R. “Behavioral Interactions between Parasites and Hosts: Host Suicide and the Evolution of Complex Life Cycles.” American Naturalist. 116.1 (1980) 77-91.

Its been a while since I've read these papers, but I remember the subject being absolutely fascinating. Even better were the discussions about potential "good" parasites.
posted by lorimt at 1:11 PM on January 21, 2006


As long as we're talking about parasites and other ingested materials affecting our bodies and brain chemistry, I wonder if there are any studies out there about these effects over a period of decades or centuries and what it's done to the chromosomal makeup of humanity in general.
As examples, those who work in highly industrialized blue-collar areas are more susceptable to exposure to chemicals that will affect them at the chromosomal level, coal miners, asbestos workers, persons in third world countries that don't have the (and I use this term loosely these days) safety guidelines put in place to safeguard the workers in more advanced countries.
Just something to ponder. How long before we all die off as a species because we've screwed up our DNA too damn much?
posted by mk1gti at 1:38 PM on January 21, 2006


Redux.
posted by meehawl at 1:52 PM on January 21, 2006


As far as correlation == causation, there's a lot of reason to think that the parasite does alter behavior. It noticeably alters the behavior of rats (makes them unafraid of kitty litter) and rats' brains are so similar to our own that rats and people are effected the same way by antidepressants.
posted by delmoi at 1:53 PM on January 21, 2006


Just something to ponder. How long before we all die off as a species because we've screwed up our DNA too damn much?

er, getting your DNA screwed up does not cause the death of a species, in fact it can be beneficial..

In some species like e.coli system shock can actual reduce the quality of genetic transcription, which produces more variation, which means the bacterial colony is more likely to survive.
posted by delmoi at 1:55 PM on January 21, 2006


Delmoi is right, if I were a fish I think having three eyes would be quite an advantage.
posted by Space Coyote at 2:19 PM on January 21, 2006


The other good thing is that, if you read, Zimmer is talking about global warming as fact, which is nice.
posted by delmoi at 2:45 PM on January 21, 2006


Kickstart70 asked: Is there a urine or blood test for toxoplasmosis?

Yes, there is a blood test.

However, if you have cats (or know someone who does), you can perform a simple, effective, and painless test in the comfort of your own home. You know that that eerie sensation when a cat seems to look right through you? Well, theirs are simply trying to communicate with yours.

Say Hello, Kitty.
posted by cenoxo at 2:49 PM on January 21, 2006


and Leucochlordium (some sort of snail parasite).

Here it is. Check out the animated gif at the bottom.
posted by brundlefly at 3:49 PM on January 21, 2006


So. How do we get rid of these parasites? I have a cat! DAMNIT!
posted by Jelreyn at 4:07 PM on January 21, 2006


I'm not a big fan of cats. Does this mean I don't have a brain altering parasite?


I always thought dog people were the normal ones...
posted by stenseng at 4:11 PM on January 21, 2006


Now if he's infecting people and then questioning them before and after, that I might buy. But I doubt he could get it by the University ethicists. The rat experiment seems pretty solid though. Why is it that articles like this never explain their human sample populations very well, if at all?

If you believe this, then most of human psychology (the whole psychosis/neurosis thing) is not a science, because controlled experiments cannot be done due to ethical considerations. (Note: This does not mean I support the conclusions of the author.)
posted by batou_ at 4:16 PM on January 21, 2006


Jelreyn
I'm afraid there's no hope for cat lovers like you and I, due to this parasite, we're condemned to a life of paranoia and schizophrenia while being strangely attracted to cat urine whereas others just. . . shy away. . . sigh. . .
posted by mk1gti at 4:16 PM on January 21, 2006


On the causality thing, the person who is most likely to own a cat could be the person most likely to be infected, so this could actually be a personality test for who likes cats. And on that front, warm-hearted women and suspicious men does seem to be the way it goes.
posted by loafingcactus at 4:23 PM on January 21, 2006


"Food for thought" indeed.
posted by hal9k at 4:30 PM on January 21, 2006


Hmm. Is this toxoplasmosis cat-friendly behavior countered by allergies? I grew up around loads of cats, so am pretty sure I've already had toxoplasmosis. Now I'm allergic and I loathe being around the creatures. Maybe my dog secreted the parasite that caused the cat allergy.
posted by cmyk at 5:22 PM on January 21, 2006


Every time I see a cat, I am compelled to ask it, "Who's the kitty? Who's the kitty?!" over and over.

As if it doesn't know who the kitty is.

Lousy parasites.
posted by milquetoast at 6:04 PM on January 21, 2006




i don't know what you're talking about, i feel fine.
posted by poweredbybeard at 6:09 PM on January 21, 2006



This is what cats look like to people with the parasites.


This is what cats look like to the rest of us.
posted by Bonzai at 7:12 PM on January 21, 2006


"infected men tend to be more jealous and suspicious."

So.... the parasites create Republicans?
posted by my sock puppet account at 7:35 PM on January 21, 2006


So.... the parasites create Republicans?
posted by my sock puppet account at 7:35 PM PST on January 21 [!]
------------------------
And therein lies my concern. Can we identify these poor, sick deluded creatures by the pets they tend to keep and therefore make it easier to eliminate or sterilize them?

Better to cull the herd than make a fatal mistake later. . .

But then again, democrats are really *cat* people, kill the dog lovers ! ! !
posted by mk1gti at 7:59 PM on January 21, 2006


Bonzai: maybe it's the hour, or the amount of coffee I've ingested, but I cannot stop laughing at that.
posted by cmyk at 8:46 PM on January 21, 2006


Actually, cmyk, I don't think it is the hour or coffee, it's just funny. I laughed for longer than my cat told me I should. Then again, maybe these are laugh-inducing parasites that have invaded us. Maybe laughter, jealousy, cynicism, and suspicion are all linked to these bugs. Taking this whole thing further, I wonder if the "bugs" in us that develop from eating too much McDonalds, Twinkies, and TV make us easily distractible and easy prey for politicians, the media, and for the shell game shyster.
posted by Sir BoBoMonkey Pooflinger Esquire III at 10:49 PM on January 21, 2006


Almost as scary as Bonzai's cat is the hand holding the cat.
posted by mullacc at 11:48 PM on January 21, 2006


Damn, that was funny, bonzai!
posted by five fresh fish at 1:02 AM on January 22, 2006


I've had cats for years and years, so I'm probably infected, yet I still fear kitty litter. This proves nothing.
posted by Larzarus at 1:43 AM on January 22, 2006


Those infected, he found, show a small, but statistically significant, tendency to be more self-reproaching and insecure. Paradoxically, infected women, on average, tend to be more outgoing and warmhearted than controls, while infected men tend to be more jealous and suspicious.

At least this somewhat explains why my family is insane.
posted by Uther Bentrazor at 7:33 AM on January 22, 2006


Anecdotal evidence is worthless, I know, but all cat owners I know drive like absolute maniacs.
posted by spazzm at 8:16 AM on January 22, 2006


On one hand, I think, wow... that's so inane and improbable that it could only be the work of a concerted, deliberate design.

And then on the other, I think noooooo! Oh god NOOOOOOOOOOOO!

Is there such a thing as being athiest because you cannot believe in a God so twisted as to create this world?

/eeyyuuugggghhhhhh
posted by InnocentBystander at 8:57 AM on January 22, 2006


This is what cats look like to people with the parasites.
This is what cats look like to the rest of us.


Sadly, to those of us that are infected, both animals are just adorable!
posted by jaded at 9:17 AM on January 22, 2006


« Older Find out what's in it before it's in you...  |  The Abdorrahman Boroumand Foun... Newer »


This thread has been archived and is closed to new comments