Te Papa Taonga Collection health hazard

Te Papa (image from www.cato.co.nz)

Te Papa caused controversy recently by suggesting that pregnant and menstruating women avoid the tour of their Maori Taonga.  Interesting was the suggestion that there was a risk of miscarriage due to the power they contain.  So is there a genuine health hazard?

Diaconis and Mostellers’ Law of Truly Large Numbers say that for a large enough sample, any unlikely thing is likely to happen, and further suggested that we notice unlikely events more than we notice likely events.  Without going into details with the maths, as an example, in a situation where something has a .1% chance of happening, if the situation is repeated a thousand times, the chances of it happening at least once rises to 63.2%, and if the situation is repeated 10,000 times, it will happen at least once with a chance of over 99.9%, i.e. it’s more likely to happen than not.  In recent months we’ve seen news reports both of someone winning the lottery twice, and a repeat of the same winning lottery numbers in relatively quick succession – good examples of both parts of this law in action.

If two things happen together does this mean that one causes the other?  Hobbes has suggested that for much of human history, life has been “brutish, short and nasty”, and in that sort of environment it certainly makes good survival sense for us to overestimate the connection between events – with less significant consequence, than failing to notice a real connection.  Particularly in emotionally heightened situations, where we search for meaning, we are programmed to overestimate the chances of a correlation or simple coincidence being due to causation.

Also in emotional situations, and where there are established beliefs, we are more likely to display a conformational bias; we look for evidence and recall information from memory selectively, and interpret it in a biased way.

So there’s been a good historical chance of miscarriage coincidentally after expose to taonga; we are predisposed to interpret this as causation; and we are more likely to remember the event than all the times it didn’t happen.  This would explain the establishment of the belief, but doesn’t answer our original question – can expose to taonga be a health hazard?

To answer that question we can look to the placebo effects evil twin – the nocebo effect.  We’re all familiar with the placebo effect, where an inert substance such as a sugar pill can produce a positive health outcome at greater than statistically average chance.  However, researchers have also found the opposite effect – for example in one study, women who believed that they were prone to heart disease were nearly four times as likely to die from it than women with similar risk factors who didn't hold the same belief.  There are cultural practices – the best know would be voodoo, that exploit the nocebo effect.

So a miscarriage occurring after exposure to taonga may simply be coincidence, or it could be correlative, where the root cause is the belief rather than the exposure itself.  So yes, exposure can be a health hazard: but not from any intrinsic power they contain, but rather from our belief that they do.