Superstitious people don't understand probability

David DiSalvo, writing in Neuronarrative, has an interesting discussion on the role of the fallacy of conjunction in paranormal beliefs. Hat tip to Vaughan from Mind Hacks for the link and connecting it to Jung's idea of synchronicity.

DiSalvo's blog post is based on an article entitled Paranormal belief and susceptibility to the conjunction fallacy in the journal of Applied Cognitive Psychology. The abstract for the article reads as follows:

"Numerous studies have shown paranormal believers misperceive randomness and are poor at judging probability. Despite the obvious relevance to many types of alleged paranormal phenomena, no one has examined whether believers are more susceptible to the conjunction fallacy; that is to misperceiving co-occurring (conjunct) events as being more likely than singular (constituent) events alone. The present study examines believer vs. non-believer differences in conjunction errors for both paranormal and non-paranormal events presented as either a probability or a frequency estimation task. As expected, believers made more conjunction errors than non-believers. This was true for both event types, with both groups making fewer errors for paranormal than for non-paranormal events. Surprisingly, the response format (probability vs. frequency) had little impact. Results are discussed in relation to paranormal believers' susceptibility to the conjunction fallacy and more generally, to their propensity for probabilistic reasoning biases."

DiSalvo explains the fallacy of conjunction as a tendency to believe that when events co-occur (or conjunct) they were ‘meant’ to co-occur, or at least were more likely to co-occur than a single event occurring alone. According to the article in the the journal of Applied Cognitive Psychology rerferred to above, the conjunction fallacy could be at the core of belief in the paranormal.

As pointed out by Vaughan from Mind Hacks, the fallacy of conjunction also features in Jung's concept of synchronicity (or meaningful coincidence). Wikipedia defines sychronicity as:

"Synchronicity is the experience of two or more events which are causally unrelated occurring together in a supposedly meaningful manner. In order to count as synchronicity, the events should be unlikely to occur together by chance."

I found it surprising to read in Wikipedia that the physicist Wolfgang Pauli co-authored an article on synchronicity with Jung, considering Pauli's views on pseudoscience and his famous quote on that topic:

"It's not right, it's not even wrong."

Those were the early days of quantum physics and I suspect that you would not find too many serious phycisists today who would consider linking physics with nonsense like synchronicity.

In closing, I believe that when looking at the fallacy of conjunction, one should also consider confirmation bias.