We are all prone to fall victim to the ‘post hoc ergo propter hoc’ fallacy. It describes the erroneous assumption that something that happened after an event was cased by that event. The fallacy is essentially due to confusing correlation with causation:
- the sun does not rise because the rooster has crowed;
- yellow colouring of the 2nd and 3rd finger of a smoker is not the cause of lung cancer;
- some children developing autism after vaccinations does not mean that autism is caused by vaccination.
As I said, we are all prone to this sort of thing, even though we know better. Scientists, journal editors and reviewers of medical papers, however, should not allow themselves to be fooled by overt cases of the ‘post hoc ergo propter hoc’ fallacy. And if they do, they have lost all credibility – just like the individuals involved in a recent paper on animal homeopathy.
Pododermatitis in penguins usually occurs after changes in normal activity that result from being held captive. It is also called ‘bumlefoot’ (which fails to reflect the seriousness of the condition) and amounts to one of most frequent and important clinical complications in penguins kept in captivity or in rehabilitation centres.
This veterinary case study reports the use of oral homeopathic treatment on acute and chronic pododermatitis in five Magellanic penguins in a zoological park setting. During treatment, the patients remained in the penguins’ living area, and the effect of the treatment on the progression of their lesions was assessed visually once weekly. The treatment consisted of a combination of Arnica montana and Calcarea carbonica.
After treatment, the appearance of the lesions had noticeably improved: in the majority of penguins there was no longer evidence of infection or edema in the feet. The rate of recovery depended on the initial severity of the lesion. Those penguins that still showed signs of infection nevertheless exhibited a clear diminution of the size and thickness of the lesions. Homeopathic treatment did not cause any side effects.
The authors concluded that homeopathy offers a useful treatment option for pododermatitis in captive penguins, with easy administration and without side effects.
So, the homeopathic treatment happened before the recovery and, according to the ‘post hoc ergo propter hoc’ fallacy, the recovery must have been caused by the therapy!
I know, this is a tempting conclusion for a lay person, but it is also an unjustified one, and the people responsible for this paper are not lay people. Pododermitis does often disappear by itself, particularly if the hygenic conditions under which the penguins had been kept are improved. In any case, it is a potentially life-threatening condition (a bit like an infected bed sore in an immobilised human patient) that can be treated, and one should certainly not let a homeopath deal with it.
I think that the researchers who wrote the article, the journal editor who accepted it for publication, and the referees who reviewed the paper should all bow their heads in shame and go on a basic science course (perhaps a course in medical ethics as well) before they are let anywhere near research again.