Predictably, the homeopaths have quickly started squealing about how unfair all this is. The BBC quotes Robert Wilson, of the British Association of Homeopathic Manufacturers, saying how "disappointed" he is:
He said the MPs had ignored evidence that homeopathy was effective. "There is good evidence that homeopathy works, for example in animals and babies, neither of which experience placebo effects."I wish I had a pound for every time I have heard this pathetic argument. It is so obviously false that it immediately reveals that the speaker either has not thought for two seconds about what they are saying, or that they simply do not care that they are bullshitting. If you do not agree, pause for a moment before reading on, and see if you can think of any ways in which a placebo effect might work on a baby or animal.
Finished? OK, here is my list of possible mechanisms, in no particular order. If you have some different ones, or can explain why mine are wrong, let me know in the comments...
- The effect is psychological, and operates upon the owner/parent. Because they expect the treatment to work, they see improvement where there is nothing, or nothing more than normal time-limited or cyclical changes in the condition. This effect is greatly enhanced when the owner/parent is highly motivated to see improvement, either because they have a strong personal belief in the treatment, or have invested time, money and credibility in it. It will also reassure the "worried well" parent/owner whose baby/animal is not actually ill in the first place.
- The effect is real, but derives from changes in the parent/owner's behaviour and emotional state. Because they know their baby/animal is receiving treatment, they become less anxious. The babies/animals pick up on this mood change and so relax more themselves.
- The effect is real but derives from changes associated with the treatment, rather than the treatment itself. For example, if the baby/animal has received extra care and attention, a change of diet or sleep patterns, and a break from work or other activities, these could have caused the improvement. Similarly, if an alternative treatment has been given in conjunction with real medicine, parents/owners may attribute any success to the treatment rather than the medicine.
- The effect is real and arises as a conditioned response to the rituals of care. If the baby/animal has previously improved after taking real medicine, then the administration of a placebo in the same way can evoke the conditioned response.
- The effect is real and arises as part of the acute phase response to an injury. Pain or inflammation evolved to stimulate the suffering organism to immobilise the injury site and to seek help. Once this has been achieved, the pain/inflammation is less necessary and can dissipate.