Talk:Behavior-altering parasite

The discussion about traits and adaptation is very arguable
e.g. see "correlation" on the table.

all good points for creative thought but minimally this section needs specific refs. otherwise -- not reference material. Delete? — Preceding unsigned comment added by 76.127.54.50 (talk) 02:40, 6 August 2015 (UTC)


 * Removed due to irrelevance to this article. All of it belongs in a more general article about parasitic behaviors and hosts' adapataions. François Robere (talk) 10:21, 17 September 2015 (UTC)

Arguable edit
I cannot approve the edit that says: "by directly affecting the hosts' nervous system". This may happen, but I have never seen any work that suggests that indirect or incidental effects, such as gut damage affecting behaviour, are not equally or even more important. I have not edited it, but could we have either an edit or a discussion please? JonRichfield (talk) 14:33, 19 April 2013 (UTC)
 * The article is missing what is probably the strongest example, rabies. For that disease it's pretty clear that effects on the nervous system are extremely important. Looie496 (talk) 15:09, 19 April 2013 (UTC)
 * I know you wanted to undo your edit, but it's actually relevant. Organisms referred to as "parasites" are usually eukaryotes, and often multicellular. Defined broadly, however, parasites may as well include bacteria and even viruses (see intracellular parasites). I'm not sure exactly how to treat this difference in the usage of the term and the consequences to the inclusion of rabies and other bacterial and viral pathogens in this article. François Robere (talk) 15:21, 19 April 2013 (UTC)
 * There are certain parasites and parasitoids that use specialized techniques to modify their hosts' behaviour directly, in a manner conducive to their own proliferation, often without harming the host in the process. The point in starting this article was to refer specifically to those organisms rather than to *any* parasite causing *any* effect to the host (I assume you've seen the former version of the page referring specifically to a bowel inflammation caused by a helminths infection). Indeed I did not start the article following a specific publication stating "we should refer to behaviour-altering parasites by this name", but rather because it makes a lot of sense as a naturally-defined group of organisms. Put differently: Those characteristics that I've specified above are distinct enough and important enough (both conceptually and from a human perspective) to justify a separate article. François Robere (talk) 15:38, 19 April 2013 (UTC)
 * I don't mind practically universally regarding viruses as obligate parasites. Certain other microbes, certainly including many prokaryotes, are certainly regarded as parasites or parasitoids too, depending on their habits. But I don't see what this has to do with my question. I definitely have no objection to including parasites that directly and specifically influence the behaviour of hosts by affecting their nervous system either; all I am bothered by is that "by directly affecting the hosts' nervous system" is not the only significant example of such effects, and this should be made clear in the text. Furthermore, I think that the inclusion of parasitoids (indeed such as rabies) should be allowed explicitly. I am not sure what you mean by "those organisms rather than to *any* parasite causing *any* effect to the host"; the title is specific enough, and no one wants to include all parasites and parasitoids. However, the title does not (and IMO should not) constrain us from including a representative range of forms of influence on the host, including many that are not mediated by *direct* effects on the nervous system. It would be very difficult to construct a really representative discussion without including other effects as well. JonRichfield (talk) 15:54, 19 April 2013 (UTC)
 * Nothing. THAT was a separate response to Looie496, properly indented and signed previously. See again.
 * First thing's first:
 * 1. Have you seen the previous incarnation of that sentence, that I referred to previously?
 * 2. "Furthermore..." - I assume you did not mean "parasitoids", but rather "intracellular parasites" and the like.
 * 3. So basically you want to include any parasite that affects the host behaviour merely by its presence, correct? Bear in mind two things: a) Every parasite affects the host negatively (and by extension the host's behaviour), or it wouldn't be a parasite but a symbiote; b) The whole point of the article was not to construct a representative discussion of how parasites and pathogens affect their hosts, but rather how certain parasites and pathogens do that. François Robere (talk) 17:11, 19 April 2013 (UTC)
 * Ah. There seem to be several levels of confusion here. No matter, let's concentrate on point 3. The title of the article as it stands is: "Behavior-altering parasites and parasitoids". I would like the article to reflect the suggested intent of that title, which describes an altogether reasonable topic for discussion. Accordingly no, I also would not like to see: "...any parasite that affects the host behaviour merely by its presence..." which would necessarily not only include nearly every parasite, but would fail to produce anything like a coherent topic. However, in line with the title and with the coherence of the topic, I would like to see a discussion of representative parasites or parasitoids that affect the host behaviour specifically in such a manner as to functionally improve the propagation success of the parasite, whether by its actions alone, its presence alone or both, and to function as it does, at least largely as a result of adaptive selection of its effect on the host's behaviour. Do I make the distinction clear? Could you mention any aspect of that line of thought that strikes you as undesirable or unsatisfactory? JonRichfield (talk) 18:26, 19 April 2013 (UTC)
 * But again, that would mean including any sort of parasite and pathogen whatsoever, and that's not the point of the article. Since most of the common infectious diseases have a person spread bodily fluids in some shape or form, usually by sneezing, coughing, diarrhoea or skin lesions. While a discussion of those can be interesting (or unnerving if that's not your kind of thing), it would essentially be a discussion of how most diseases affect people. The point of the article wasn't that, but rather to focus on a certain group that has specific traits. Now, referring to the name you should make this distinction: Influenza does not cause a behavioural change in the host; whatever change the host experiences is a side-effect of the infection, not as a direct result of the virus's actions. Hence, in the strictest sense, it is not behaviour-altering. We can make the distinction in the article clearer (I did ask you about the ), but we should not broaden it to behavioural effects of infectious diseases which is a totally different topic. François Robere (talk) 11:17, 20 April 2013 (UTC)


 * François, I understand your point, but I appear to have some difficulty conveying mine. Logically there is no reason why (certainly not "all diseases", but at least microbial and other parasitic) diseases should not be discussed in this manner and context; you have not said why adaptively behaviour-changing parasitic diseases should be excluded. You might argue rightly that there are too many such diseases to admit such an article as a practical measure, but our articles are not supposed to be exhaustive treatises on open-ended topics, and no one, least of all I myself, would argue that the article should cover all parasites/oids, nor even all that directly control host activity in specific adaptive ways by alteration of the nervous systems. I suspect that a very modest expansion of the article would suffice. I would have no objection to such an inclusive article, if properly written, in particular because it would (certainly should!) be a combined effort by several editors. Furthermore, if there were a material reason to confine the article strictly to the changes you are interested in, that would rob the article of much of the benefit of the wider perspective on the scope of such changes it would offer the reader. As for your objection to the inclusion of influenzal sneezes, I protest that your distinction is at once artificial and unsustainable; to any empirical observer a change in frequency of sneezing and nasal discharge most certainly would be a change in behaviour and it would be adaptive from the point of view of the virus, and incidentally its causes are in fact achieved via at least peripheral nervous stimulation. To argue that that is in even the "strictest" sense not behaviour-altering not only would be inconsistent, but confusing to the reader. You might as well argue that the rabies virus achieves its effects indirectly by attacks on the neurons' DNA, instead of the messages that they emit.


 * None the less, if you were to insist that the article should be so restricted and I were to insist that it should be wider in scope, then you could well invite me to mind my own business and write a different article elsewhere under a different title to my own taste. Unfortunately that would leave us with an outstanding problem (probably you in particular, since you would have the task of defending this article against other editors who noticed its incompleteness in the context of its title and helpfully insisted on expanding it until it had grown to the very proportions that I have suggested, or until some others complained that we had a fork and that merging the article was overdue). That problem is that the function that you have been trying to keep segregated does not match its current title, the very title that prompted my reaction to its inadequacies in the first place. If you do indeed insist, then the best approach would be to move the article to a new name that matches your intention more explicitly as well as precisely. You surely accept that "Behavior-altering parasites and parasitoids" does not mean "Behavior-altering parasites and parasitoids that adaptively alter host behaviour strictly by direct alteration of host nervous systems", and that as it stands it comprehends far wider classes of subject matter? Conversely, I assume that you agree that such an amplification of the title would be at once less aesthetically acceptable and less useful to readers than something shorter?


 * Now, here I at least encounter a difficulty; I struggle to find a title that would combine desirable succinctness with necessary clarity, so much so that personally I prefer to maintain the old title with the amplifications of text that I propose. However, that would be tendentious unless you are now persuaded, which is not my impression. So I have done a bit of thinking, not to my satisfaction, I grant, because I find it difficult to compose anything concise to cover all four or five aspects of the intended constraints. English is after all not French. The best I have managed so far is something like "Neurological parasitic behaviour adaptation". (In that form "parasitic" could cover both parasitoids and parasites.) But no doubt there are better alternatives. JonRichfield (talk) 13:35, 20 April 2013 (UTC)


 * I've understood your point a while ago. As I said, it is a matter of definition. You define plants as having a cell wall, being immobile and performing photosynthesis. You define mammals as being warm-blooded and having mammary glands. You expand or contract your definition according to various rules, heuristics and end-uses. Logic is only a means to that, and it's not yours alone to use.  I have: The point in starting this article was to refer specifically to those organisms rather than to *any* parasite causing *any* effect to the host; it makes a lot of sense as a naturally-defined group of organisms. Put differently: Those characteristics that I've specified above are distinct enough and important enough (both conceptually and from a human perspective) to justify a separate article; Every parasite affects the host negatively (and by extension the host's behaviour)... The whole point of the article was not to construct a representative discussion of how parasites and pathogens affect their hosts, but rather how certain parasites and pathogens do that; While a discussion of those can be interesting (or unnerving if that's not your kind of thing), it would essentially be a discussion of how most diseases affect people. The point of the article wasn't that, but rather to focus on a certain group that has specific traits; behavioural effects of infectious diseases which is a totally different topic. As I said - it is a matter of definition (as, by the way, many things in biology and medicine are). If you want to broaden the definition to cover all effects of pathogens etc. (since all of them eventually affect their hosts' behaviour) than you will have an article that at best will comprise two segments: "Body fluids and dander" and "complex behaviour"; the first will essentially cover sneezing, coughing, excrements and puss, and the second will be the interesting part where you discuss how some animals bring about complex behaviours in their hosts by directly interfacing with their motor control and decision making. At worst that article will actually refer to "how those bipedal creatures exhibit an increased tendency to self-injury (possibly to self-medicate) when their pancreas malfunctions" (because, you know - that's altered behaviour as well, and while we're at it - what's the point in focusing only on pathogens when there's a whole world of behaviour-modifying diseases to write about? This small article will probably just get gobbled up by that more comprehensive one). First, I don't know of any neural involvement in the flu, but even if there is this isn't the point. The point is this: You wish to ignore the etiology of the changes, expanding causality to an unknown degree, and focus merely on the symptoms. For that there are already the articles about symptoms and transmission . François Robere (talk) 17:23, 20 April 2013 (UTC)


 * François, we disagree radically on all those points. That is neither here nor there. The fundamental problem is not which if us is right beyond all question, (I am naturally, but never mind that for the present!) but rather how you will either prevent the majority of readers from misunderstanding your intention because of the wording of the title, or the majority of editors from boldly adding (sound or unsound) material relevant to the title, in direct contravention to what you intend or prefer. By definition that will not be their fault, but the fault of the party who elected to use that title. Remember, the article anyone writes is not his possession and he has no special rights in the matter whatsoever. Therefore: either you change the title, either along the suggested lines or a brilliant creation of your own (merely putting a long explanatory essay on your intentions into the lede will not suffice; that is not what the lede is for) or you put up with all valid and relevant augmentations. This BTW is no threat; I will not be undertaking any action in the matter, unless I see what I take to be a burning deficiency, and believe me, I am not short of alternative occupation, but if you choose the title, you choose the consequences. You could of course retain the title and start edit wars in the article to punish perpetrators, and slanging matches in the talk page to intimidate them, though I should expect you to take a more constructive course, but that is up to you, both the choice of action and the responsibility. Cheers for now. 18:24, 20 April 2013 (UTC)
 * Thank you for your advice. François Robere (talk) 11:42, 21 April 2013 (UTC)

Fleas and cats
Mention if fleas cause feral cats to fear people less in order to get their eggs spread around human habitations. Jidanni (talk) 01:01, 25 July 2013 (UTC)
 * Hello Jidanni,
 * If you can please provide a source citation it would be most beneficial. François Robere (talk) 17:24, 25 July 2013 (UTC)

Work is required
People come here to read about rabies, horsehair worms, taxoplasmosis, wasps injecting neurotoxins, crabs that are sex-changed then forced to protect parasite eggs and the cordyceps fungus. No one is here to read a treatise on the fitness landscape of the parasite-host interaction.

Further, it looks like this article is the result of an argument between people that are too literal over the title and people who know what the article should be about. It should be about mind controlling parasites like all the articles linking here suggest it is, not about how the flu can alter my behavior into making me lay down on a bed. — Preceding unsigned comment added by 72.219.226.185 (talk) 19:32, 15 February 2015 (UTC)


 * Indeed. I've removed all the irrelevant material and integrated the relevant material into the rest of the article better (see this ). François Robere (talk) 10:24, 17 September 2015 (UTC)

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Add a list of known behavior-altering species?
I think this is a topic deserving of a list of known species, either on this page or as a separate page. Thoughts? KingSupernova (talk) 01:10, 27 July 2017 (UTC)
 * When writing this article I actually tried to incorporate as many examples as possible into the text itself; it may be a better idea to move most into a dedicated section. Could sort according to phylum, mechanism of effect, or both. François Robere (talk) 09:55, 27 July 2017 (UTC)

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Causality/evolution fallacy?
A couple of the “explanations” for evolutionary adaptations described in this article seem dicey. For instance, in the example of hydrophobia amongst rabies-infected hosts, the author suggests that the “purpose” of this trait is to prevent the host from “drinking so that the virus won’t be washed down into the stomach and made unavailable for infection by biting”.

This sort of “evolutionary causality” argument is really not the most scientifically sound explanation. Although this particular phenomenon observed in rabies-infected hosts may in fact confer a survival advantage to the virus, the result itself was not purposeful—the fact that the virus accumulates in the oropharynx occurred passively, and the survival advantage that resulted was purely coincidence.

Describing these evolutionary adaptations can be very difficult to word in such a way that this fallacy is avoided. I’m going to try to take a crack at it, but I welcome anyone else’s efforts to improve these examples if you agree with my observation, thanks! Alanrobts (talk) 22:55, 25 September 2022 (UTC)
 * Agreed. Is this clearer? François Robere (talk) 13:57, 12 March 2023 (UTC)
 * Sorry for the belated reply, but yes, thank you! Alanrobts (talk) 23:29, 17 May 2024 (UTC)

Addition of galls?
Couldn't help but notice there is no mention of galls. I'm not sure to what extent it is plant behaviour versus plant genetics versus other that is being tampered with, but surely it is worth a mention? While not as flashy as other organism level examples. Galls come in an obscene variety with many being species specialised as the galls creation and type are created specific to the parasitic insect/fungus species. Worth looking into adding it? Or is it beyond this articles scope. 220.233.8.16 (talk) 08:21, 12 March 2023 (UTC)
 * Done. Galls are beyond the scope of this article (they're structural, not behavioral changes), but they could be interesting to note in the See also section. François Robere (talk) 13:20, 12 March 2023 (UTC)