From Christopher Whitfield
Feedback revisits the placebo effect (18 October) that you discussed earlier (23 August, p 36). Doctors used to visit patients in their homes: the request to call on a very sick toddler was common enough. Not infrequently one was greeted by a lively toddler and a very relieved if somewhat apologetic mum. Yes, the patient had showed signs of rapid improvement shortly after the phone call was made.
If it could be shown that the ability to believe, however illogically based, was genetically advantageous this would explain all sorts of phenomena – placebos, religions, flat Earthers, cults and politicians for a start.
• Having recently had an ill toddler at home, we are reminded that they can go from appearing quite ill to very lively and back several times in the course of a day – nothing to do with placebos at all. But, yes, it seems entirely plausible that gullibility could have a genetic basis – see for example our special issue on belief (28 January 2006, p 30).
London, UK
