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Comment by tgv | Hacker News Reader

I don't see anything in that article that makes the conclusion inevitable. It's a remarkable correlation for sure, but unfortunately it doesn't go beyond that. There's no pathway from infection to leadership (just a vague hypothesis that doesn't resemble the mechanism in rats and hyenas), and it doesn't look as if they looked at uninfected pack leaders. Perhaps pack leaders or strays eat more dead cat, or some other intermediate host of T.gondii. Perhaps they sampled in the wrong time frame. The full article might have more info, but the linked one doesn't.

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I haven't read the paper either, but I must say the operation of parasites as elements in complex biological super-systems is absolutely fascinating. Ants that march to the top of trees under the influence of fungus spores trying to be eaten by birds. Fish that commit suicide by swimming toward predators as part of a parasitic lifecycle.... evolution is truly miraculous.

Another apocryphal story is cats carrying Toxoplasma Gondii make some people really like cats. So maybe mad cat lady syndrome is treatable with drugs :)

Who knows what super-systems we are unwittingly a part of. That seems an interesting area for big-data + AI hypothesis synthesis - we may find new explanations or even whole new branches of behaviour in psychology.

Things also get interesting if you look at economic and social systems in this context.

https://pubmed.ncbi.nlm.nih.gov/31980266/

They looked at animals that were and were not infected, throughout their lives, and saw what they did, so they knew whether the animals were infected or not before they became pack leaders. From the article:

>The team looked at 256 blood samples from 229 wolves, which had been carefully watched throughout their lives, and had their life histories and social status recorded. Meyer and Cassidy found that infected wolves were 11 times more likely than uninfected ones to leave their birth family to start a new pack, and 46 times more likely to become pack leaders — often the only wolves in the pack that breed.

Havent read the paper, but your quote doesn't change the core point that it could be correlation.

E.g. perhaps aggression makes them more likely to eat infected animals and also more likely to challenge for leadership.

I had this thought but doesn’t the pack mostly eat the same thing?

Not those that set out on their own, and thus are more likely to catch rodent while alone than feasting on big prey with the pack...

Unless they can pinpoint the infection and a subsequent behavior change, it's not super conclusive.

It's like concluding catching an IST makes you more promiscuous, even if that would likely be supported by statistics...

> Not those that set out on their own

That doesn’t work because they knew the full life history. They knew whether they were infected before they set out on their own or not.

That's misunderstanding brohee's post, which isn't talking about them leaving the pack but about them hunting individually before that time.

Which mightn't be what wolves do but that doesn't matter, it's a thought experiment.

> Perhaps they sampled in the wrong time frame. The full article might have more info, but the linked one doesn't.

The data was collected over nearly 27 years, the link to the full open access paper is in the references; https://doi.org/10.1038%2Fs42003-022-04122-0

The abstract alone already provides fodder against the pack-leader hypothesis: animals in a cougar domain are more likely to get T.gondii, and it might have altered the cougar's behavior instead, which would be more in line with the proposed mechanism behind rat and hyena behavior modification. And I think the only one that's got more decisive evidence is the one where the rodent becomes less afraid of a cat's smell.

Not saying it can't be the case. But the linked article is bad (ok, I should have seen that coming), and there's a lot left to disprove before the conclusion can be drawn. Yet the reactions already want to test politicians for infection, as if there were no leaders before cats were commonplace, and as if it isn't known to be bad for pregnancy.

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