Bad luck can be a self-fulfilling prophecy - something those more superstitious might want to keep in mind this coming Friday.
An unlucky trinity of superstitions is set to align as a full moon falls on traditionally the unluckiest day of the week - Friday, which also happens to be the 13th.
On Friday the 13th driving a car or doing any form of cleaning is said to be unlucky, as is setting off on holiday - and don't even think about sharemarket trading.
On full moon nights, emergency rooms are said to overflow and crime rates supposedly increase. When asked for comment on full moon statistics the police refused to be drawn into the superstitious debate.
Friday and the number 13 have been seen as separately unlucky in Western culture for centuries before they came together as the ultimate bad luck day about 200 years ago.
Add to that the expectations of bizarre behaviour for which the full moon is often a scapegoat and this Friday could be downright terrifying for some.
It has been 14 years since a full moon and a Black Friday fell on the same day and it won't happen again until 2049.
Victoria University professor and paranormal researcher Marc Wilson said he had never seen any objective evidence that Friday the 13th meant anything more than just another day on the calender, but people seemed to have an attraction to the unknown.
"The people who are most likely to be susceptible to bad luck are those who worry about it, so it becomes a self-fulfilling prophecy because that person has been tense and anxious."
Wilson said people who engaged in superstitious activity were trying to take control of the unknown. He said the most superstitious professions were sports people, doctors, nurses and surgeons - for whom the difference between a good day and a bad day might be life and death.
A reality check from the New Zealand Sceptics' Friday the 13th guide states that no reputable scientist would say luck existed. The organisation say every time a Black Friday comes along, a fuss is made, meaning unlucky events on that day are more likely to be remembered.
Hopefully for all of us, only the wolves have a howler.
- Sunday Star Times