How Your Cat Is Making You Crazy | Hacker News Reader

How Your Cat Is Making You Crazy

theatlantic.com

182 pointskawera75 comments

How can they call it a parasite?

It's clearly a commensal symbiote: for cats, it assists them in catching prey.

In rats and humans, its changing prevalance helps adjust the relative expression of different behavioral strategies, faster than inheritance alone could.

For example, the risk-taking and increased libido in rats shifts the infected slightly along the K-strategy/r-strategy reproductive spectrum. In some environments that's a win, others a loss, but the T.gondii increases rat behavior diversity, and thus the species' adaptability.

Similarly, its modulating effects on human suspicion, gregariousness, investment in fitness-signalling (clothing), and obedience/trust sometimes help and sometimes hurt, depending on an ever-changing environment.

What if we 'cured' this and found the resulting human populations were less resilient against war, ecological stresses, and rapid technological/cultural change?

(I'm only half joking. And a meta-parasite is making me write apologetics for other parasites. And this entire comment is just a long way of saying "I, for one, welcome our new Toxoplasmosis gondii overlords" without getting immediately downvoted.)

Semantics point/question:

The T. gondii, as viewed from the cat's perspective might be a symbiote, but from the rat's perspective, is certainly a parasite, isn't it? The T. gondii is benefiting at the expense of the rat. Do biologists classify things as both simbiotes and parasites?

I think some rats also benefit: their adventurousness and increased sexual activity isn't always penalized with death, and even when it is, female rats prefer the infected male rats. So even if they live fast and die young, they may leave more offspring.

Whether this is a net benefit at any one time probably depends on lots of things, and especially relative rat/predator populations. Just as human reproductive preferences seem to change in relation to wealth, population density, and life-expectancy.

Regarding semantics, I do think something can be both a symbiote and parasite. When I first learned of 'symbiosis' it was in the context of mutually-beneficial relationships, but it seems the term can be more general. Wikipedia says scientists sometimes disagree whether 'symbiosis' should only be used to describe 'mutualist' relationships (where both benefit) or also 'parasitic' (one benefits and other is harmed) and 'commensal' (one benefits and other neither harmed nor helped) relationships.

I should have used the word 'mutualist' in my above post, as that's what I was intending to imply. But the conjecture is intentionally fuzzy about whether the benefit is to the individual (it perhaps sometimes is) or the species (it perhaps always is, as long as both infection and non-infection are well-distributed).

think of it as an agent of accelerated evolution

> Do biologists classify things as both simbiotes and parasites?

I don't know about that, but I know ichneumonid and braconid wasps have built exactly that relation with viruses: http://en.wikipedia.org/wiki/Polydnavirus

For people with cats, some reassuring text:

  Given all the nasty science swirling around this parasite, is 
  it time for cat lovers to switch their allegiance to other 
  animals?

  Even Flegr would advise against that. Indoor cats pose no 
  threat, he says, because they don’t carry the parasite. As 
  for outdoor cats, they shed the parasite for only three 
  weeks of their life, typically when they’re young and have 
  just begun hunting.

hmm not so reassuring...

Are you kidding me? Besides the "Indoor cats pose no threat, he says, because they don’t carry the parasite", what other kind of reassurance you want?

Not to mention the fact that people seem to live on fine with domestic cats for the last 2,000 years, with no casualties...

It also kind of explains the pyramids... it wasn't aliens, it was cats! :-)

I know humor is sort of frowned up on HN but that was hilarious.

Downvoted for enjoying yourself.

Of course the author says that! He has cats, he must be infected too!

But seriously, the claim wasn't that the parasite immediately kills people but makes them more disposed towards self-destructive behavior. The fact that, 2000 years after people started living with cats, humanity yet survives isn't really absolute proof to the contrary.

Well, article claims that people really have started living with cats (that is, keeping them as pets) since 18th century in France, which is also when schizophrenia started to spread. So yeah, just over a century later and by the looks of it humanity is lucky to still survive!

Imagine how different life would have been now without that crazy infected folk who like dangerous driving and become obsessed with insane ideas. =)

By the way, can anyone clarify—is there a way to detect toxoplasmosis even in latent form? It seems from Wikipedia article that blood tests can't provide reliable results here.

Maybe we have evolved with the influence of cats, who are really in power. They use us to achieve their objectives (mining for gold for some reason maybe?). The toxins keep us under control. It makes so much sense!

Because i have an outdoor cat! When it was a kitten it would go outside hunting. And it wants to kill me.

> Compared with uninfected men, males who had the parasite were more introverted, suspicious, oblivious to other people’s opinions of them, and inclined to disregard rules. Infected women, on the other hand, presented in exactly the opposite way: they were more outgoing, trusting, image-conscious, and rule-abiding than uninfected women.

This reminds me of a lot of cat-people I know. But that might just be selective recall.

We have six cats at the house here, hence the username 'nekojima', Japanese for 'cat island'.

I have long suspected a parasitic role (either us or them for attention rather than brain damaging) or an element of craziness in our having so many cats. So far our own scientific analysis has been interrupted by near constant feline requests for attention, food or having to clean a little more than 'normal'.

...'nekojima', Japanese for 'cat island'.

Off topic but interesting. Guess "Iwo Jima" follows suit. I learn something new here every day.

Yep, Sulfur Island. (http://jisho.org/kanji/details/%E7%A1%AB%E9%BB%84%E5%B3%B6)

> hence the username 'nekojima', Japanese for 'cat island'.

It's actually 'shima' for island. Not sure if 'jima' works too, but shima is definitely more common.

(insert obligatory off-topic warning here)

> It's actually 'shima' for island. Not sure if 'jima' works too, but shima is definitely more common.

Correct, "island" is shima, but in this case we have a phenomenon in Japanese known as "sequential voicing" (連濁, rendaku) in which the first syllable of the second word of a compound is changed from an unvoiced consonant to a voiced consonant. This is particularly common when dealing with native Japanese compounds; i.e., compounds using words not derived from the imported Chinese pronunciations of characters. So "island" (島) by itself would be shima, but when used as a suffix, the initial consonant sh becomes voiced to j, and thus jima. Another example is "fire" (火), pronounced hi alone, but voiced to bi as the second half of words such as "fireworks" (花火, hanabi).

The 'ji' (じ) uses the same kana as 'shi'　(し), just with some tick marks. Which sound is used in a compound word depends on the previous syllable. So, by itself, yes, it's "shima", but in a compound it could be either.

Iwo Jima, according to Wikipedia, is "Sulphur Island", so I would guess that either Iwo or Jima is OK, too.

I loved this talk on Toxo and its effects on freewill by the always incredible Robert Sapolsky.

http://www.edge.org/3rd_culture/sapolsky09/sapolsky09_index....

Sigh - I spent over 2 hours talking with this reporter trying to help her understand the limitations of this guy's studies, but she doesn't seem to have taken on board anything I said... Of course, he could be right and it could also be that the X-rays emanating from a TV really do protect you from malaria. Or it could be that you watch TV indoors and so don't get as many mosquito bites. So, yes, it could be that Toxo causes increased risk-taking ... OR it could be that risk-takers drive their cars more crazily and do things that cause them to be slightly more likely to get infected! There can also be a strong socio-economic bias to infection rates and it could be that people from Czech farms are more likely to be infected from eating vegetables from their cat-feces-infested gardens and more likely to be in a car crash driving home wasted after a Polka 10 miles away in the nearest town in a Lada held together with superglue while their affluent city friends take the bus or drive a BMW and eat vegetables from a mass-production farm in the Ukraine. Etc., etc. On the other hand, the animal data are real (good, controlled experiments) and so it is TEMPTING to believe but the human data are really not good experiments. WAY too many "confounding variables" and no controls. There is one study with US military recruits that found a very slight increase in the likelihood that if you entered the army Toxo-negative and became Toxo-positive while in the army you were ever so slightly to be discharged with a diagnosis of schizophrenia than someone who stayed Toxo-negative. But the difference was not statistically significant, in my opinion (predict 13 patients would be discharged with schizophrenia in the Toxo-positive group and saw 15 were - NOT a significant difference).

Bottom line, it's crap science and of course he could be right but so could the guy who says the world will end this November...

I had a hard time reading this and extracting "the limitations of this guy's studies", do you have any more details?

If one of the main risk factors for the parasite is exposure to cats, how exactly is that increased by "risk-taking behavior"? Are cats considered risky?

You wrote a lot but none of it was persuasive. Other than random exaggerated "possibilities," what reason do you have to say it's crap science?

This dude knows nothing about cats and crazy. Cats make you crazy by pawing your face all night for attention and sleeping all day because they're tired from being awake until dawn.

"Cats make you crazy by pawing your face all night for attention"

For a while one of our cats was waking me up by climbing to the top of a wardrobe and then launching itself onto my stomach as I slept from this considerable height - which appears to be the cat equivalent of BASE jumping.

The fact that I endured this behaviour a few times with relative good humour probably indicates that I probably have this mind control parasite!

hahaha, word. What makes you crazy is that cat wants attention when you are busy or sleepy and wants you away when you want to pet it, screams and breaks stuff when it's hungry and scratches your furniture.

and this http://www.doggiestylish.com/store/images/wordpress/uploads/...

Cats are awesome!

But you still keep the cat, huh? That must be the parasite at work. Actually, now I have a whole new perspective on cat owners in general, and why they put up with their pets..

I can't believe I read through the whole thing - it started off kind of crazy. Still, just as Flegr himself says, the change in behavior is minimal - chances are high that the average individual's life wouldn't be much different whether he/she had the parasite or not.

Still, it's amazing how such a primitive organism can change your brain's function - makes you wonder if there's a parasite that's making people stupid/smart/lazy/etc.

Perhaps even consciousness itself is... no. Host. Must. Not. Think. Such. Thoughts.

Dennet ("Consciousness explained") does suggest that important parts of what we call "consciousness" are cultural, rather than inborn...

Blackmore in her introductions to consciousness suggests something related: that consciousness is an a concept (or illusion, to her) only widely known because it became a social meme.

Here's a thought. Helen Fisher's research categorises people into four dominant personality types based on levels of neurochemicals: http://socionist.blogspot.com/2009/04/helen-fishers-types-ex...

For dopamine, which according to the cat article is elevated in Toxo-infected humans, the associated personality type is "risk-taking, curious, creative, impulsive, optimistic and energetic". Plus the associated decrease in fear response in rats: who does that sound like?

i.e. I wonder what percentage of entrepreneurs are Toxo infected?

Here's the question, though: are the risk-taking humans risk-taking because they're infected, or are they infected because they're risk taking. Correlation, unfortunately, doesn't imply causation.

The "fatal attraction to cat urine" studies are somewhat imperfect [1]. I'm friends with a student who's doing similar studies with mice but with better spatial discrimination . The consensus seems to be that while the fear response goes down, the idea that it's attractive to the rodents is more difficult to replicate.

[1] Free at http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1690701/?tool=pu...

Your question reminds me of a word one of my programs coined: entrepreneuropsychology.

"We evaluated 148 case patients with recent T. gondii infection and 413 control patients. In multivariate analysis, an elevated risk of recent T. gondii infection was associated with the following factors: eating raw ground beef (adjusted odds ratio [aOR], 6.67; 95% confidence limits [CLs], 2.09, 21.24; attributable risk [AR], 7%); eating rare lamb (aOR, 8.39; 95% CLs, 3.68, 19.16; AR, 20%); eating locally produced cured, dried, or smoked meat (aOR, 1.97; 95% CLs, 1.18, 3.28; AR, 22%); working with meat (aOR, 3.15; 95% CLs, 1.09, 9.10; AR, 5%); drinking unpasteurized goat’s milk (aOR, 5.09; 95% CLs, 1.45, 17.80; AR, 4%); and having 3 or more kittens (aOR, 27.89; 95% CLs, 5.72, 135.86; AR, 10%). Eating raw oysters, clams, or mussels (aOR, 2.22; 95% CLs, 1.07, 4.61; AR, 16%) was significant in a separate model among persons asked this question. Subgroup results are also provided for women and for pregnant women.

Conclusions. In the United States, exposure to certain raw or undercooked foods and exposure to kittens are risk factors for T. gondii infection. Knowledge of these risk factors will help to target prevention efforts." http://cid.oxfordjournals.org/content/49/6/878.full

After reading this article (which was very enjoyable by the way), I am now curious to find out if I myself may be the puppet of some parasite. Is there any way to find this out easily?

Radiolab delved into this a bit in their show "Parasites" from a while back. You can listen to the relevant segment under "The Scratch", although I recommend the whole thing, of course:

http://www.radiolab.org/2009/sep/07/

When and if this research is sufficiently established, people will most likely have an averse (and perhaps unwarrantedly so) attitude to having cats as pets.

Or maybe we will start vaccinating the kitties when they are young enough to start hunting.

I guess it depends on how easy and effective treatments are.

Pregnant women already routinely get advice not to clean litter boxes and such, which, anecdotally, sometimes translates into getting rid of the cat.

There's more information on this parasite on Wikipedia: http://en.wikipedia.org/wiki/Toxoplasmosis

Other links on the 'net that I've found are reporting (without any citations) that the parasite can be detected with a blood test (according to wikipedia, not true) and that it cannot be treated (again, according to wikipedia, also not true).

I've seen articles about this parasite pop up over at least the last 5 years. If it was a truly serious problem I'm sure there'd be more information about it. It smells a bit like FUD though.

Can anyone else elaborate on this further?

"If it was a truly serious problem I'm sure there'd be more information about it."

That's not really how science/epistemology work.

A search for Toxoplasmosis on G-scholar reveals that this parasite is in fact a problem for immune compromised patients and infants. Although I do not think WebMD is a reliable source, another comment here cites them to indicate that infections are usually cleared up by our immune system. This appears to be plausible, but because the parasite enters cells, and can hide in a latent phase, your immune system may be unable to clear the infection permanently. Because the parasite can halt the cell cycle, it may be able to hide indefinitely. I would not be concerned about a latent parasite, but its re-emergence may become a problem if your immune system becomes compromised.

A correction to your statement that, according to wikipedia, the disease cannot be tested by blood sample. Wikipedia, in fact, stats that it can be tested by blood or other tissue, but only if the parasite is active (non-latent).

Regarding its effect on behavior, the parasite seems to increase dopamine levels and possibly inhibit fear response. Since the increased dopamine is caused by an enzyme made by the parasite, this probably only occurs during a full scale infection. The inhibition of fear may occur while the parasite is inactive, if the parasite is able to enter cells in your amygdala. I do not see this inhibition of fear as long-lasting, except perhaps in extreme cases.

One disclaimer, I grew up with a few cats, so I may have been, or am currently, infected. I cannot rule out that this parasite is manipulating me to write this comment. Now I'm off to find some cat pee. Can't get enough of that smell, mmmmmmmm.....

More technical wiki article: https://en.wikipedia.org/wiki/Toxoplasma_gondii

WebMd [1] and some other places [2] talk about it like it's a bacteria that your immune system fights off then you are safe from for the rest of your life. They don't seem to talk about any long term effects, and focus on just the risk the acute symptoms can have.

[1] http://www.webmd.com/food-recipes/food-poisoning/toxoplasmos... [2] http://www.pamf.org/serology/clinicianguide.html

Five years isn't all that much time as far as bio-med research is concerned. I would expect to start seeing definite results in maybe a few years.

As for detection and treatment, the subject being discussed in the Wiki article is the effect of initial infection. The parasite sticks around in a latent form after being "fought off" and is being hypothesized to have additional long-term effects.

This is a repost of an earlier submission at http://news.ycombinator.com/item?id=3573447

(It was probably posted previously before that)

The article is very interesting but seems to inflate the fact that if you have a cat you're most likely going to contract T. gondii.

If indoor cats don't carry T. gondii and outdoor cats only carry the parasite for three weeks of their life, isn't the risk of getting this parasite very low since there is only a three week window? Perhaps I'm misinterpreting this. Please correct me if I'm wrong.

I think T.gondi is the reason kitten videos are so popular on YouTube - CDC should look into this - it might be a global pandemic ;)

I want to do an experiment: A/B testing landing page with and without cute kitten photos. I'm sure the one with cats photos will have much higher conversion rate.

I also believe baby humans pass on a parasite that influences the parent to take and share voluminous photos and to regard every ounce of vomit from the child as a work of genius. This merits further study.

Hold on, my cat is trying to type sometjfkd a;dsjkf jdfmfddddddsa

fidddddddddddddddx fj

I love that the scientist at the heart of this story looks like a young Doc Brown

Finally! A scientific explanation for http://www.youtube.com/watch_popup?v=sP4NMoJcFd4 !

I'm glad he was smart/sane enough to even think about going to the lab. When something is messing with your mind, can you even think of such logical reasonable things?

You've never heard of a mad scientist? You know "Mwahaahahaaa..." and all that.

I'm surprised, it's a total cultural meme.

Probably dates back to Newton and those other alchemists who were really fascinated by the, um, transformative properties of mercury.

Seriously, OC probably means this: When you're having seemingly psychological affects/things that are just "part of who you are," it's almost impossible to begin to think that it might be some outside force.

I used to take a medicine which I thought was fine; in the mean time, I developed worse and worse depression, anxiety, and all the time I thought it was a reasonable reaction to stuff in my life. THEN I got paranoid and thought my best friend and boyfriend were out to get me. Finally, something snapped. Finally, I thought, "whoa, this is not me." Turns out it was ALL the medicine. Yes, I had reasons to be depressed, but that's just not my type. Ended the medicine, ended all the side effects.

It only took 3 years and a CRAZY extent of the side effects for me to realize it "wasn't me."

Note how this linked article is from March 2012. And today is only February 10th :-)

Print magazines date their online articles to match the print issue.

It's the early edition :)

So what's the treatment for toxoplasmosis infection? Can I buy something OTC?

No OTCs, but Minocycline looks promising, and it's cheap.

http://www.ncbi.nlm.nih.gov/m/pubmed/1885421

Also, Maralone or something similar that uses atovaquone and proguanil.

Really hoping alcohol is the cure...

Looks like there is something to the "crazy cat lady" after all.

Except the supposed behavior alteration in women is increased social activity, attention to appearance, neatness, and aversion to the smell of cat urine.

Average alteration.

Given the article's suggestion that some people react differently to infection (as in the schizophrenia/immune-system discussion, and not just by gender), plus the similarity of cat ladies' behavior with infected rats in some dimensions, a link between this parasite and the 'cat lady' archetype is not an outlandish conjecture.

I have four cats and they are all indoors, so I guess I'm safe. But even if they weren't indoors, and I was vulnerable to this parasite, it wouldn't matter. I love them too much. The heart overrules the head in this matter.

> The heart overrules the head in this matter.

I guess the parasite is working.

Could be the parasite talking... :-)

Ive dated 2 girls with cats, both of them turned out to be very crazy. Cats are a deal breaker for me. Crazy cat lady isn't the exception, its the rule. The ladies will argue about this to no end, don't waste your time, they are crazy. I wish I could send this note back to myself 18 years ago.

I was tempted to mock your comment, but instead, out of a general wish for you to be happy even though I don't know you, I would really recommend that you expand the size of your study group.

I'm sure if you think about it you can find some other similarities between these two women that may account for their issues. For example, both of them were apparently attracted to you...

Excellent point! I have to try harder to not fall victim to the fallacy of post hoc.

> JAROSLAV FLEGR IS NO KOOK

FUNNY HE SURE LOOKS LIKE ONE

My cat is so self reliant I love any attention he gives me.

But then again, I raised him.

But, WTF, cat stories on Hacker News? I don't know what to say!

Maybe you should read the linked article before commenting on it- it goes well beyond just cats ;)

Reply on news.ycombinator.com