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A University of Toronto statistics professor analyzed unexpected deaths in Ontario from 2009 to 2023 and found death rates on Friday the 13th, Halloween and full moons were close to normal. The research also examined why superstitions persist and how confirmation bias keeps them alive.
A University of Toronto statistician has determined that Friday the 13th is not an unlucky day, based on an analysis of unexpected deaths in Ontario from 2009 to 2023.
Jeffrey Rosenthal, a professor of statistics, published the study with co-author Jennifer Dmetrichuk. It appeared in July in Chance, a data-based quarterly magazine, under the title Friday the 13th, Full Moons, and Holiday Blues: Ontario Death Date Distributions. The paper examined whether bad events are more likely to occur on Friday the 13th. Rosenthal found mortality rates on Friday the 13th, Halloween and full-moon periods were close to the overall rate.
Rosenthal does not describe himself as superstitious. As a scientist, he has always relied on hard data to find patterns and trends and to test hypotheses. His interest in the topic became personal because his birthday falls on Oct. 13. In the late 1990s, Rosenthal wrote a preliminary computer calendar program and used it to calculate the day of the week he was born.
He recalled saying, Oh that is interesting. That is on a Friday. Rosenthal knew Friday the 13th has long been considered unlucky. He wondered whether believers in the superstition would assume he was destined for a life of bad luck.
It made the superstition feel more personal and indirectly sparked the idea for a study. The study was not his first look at luck and superstition. In 2018, he published a book titled Knock on Wood: Luck, Chance, and the Meaning of Everything, which applied scientific thinking to chance and superstition. The latest research had been on his mind for a while.
Rosenthal Analyzes Death Data for Superstitions
He said it is one thing to say superstitions are wrong, but as a scientifically-minded person, he wants to investigate them scientifically. The opportunity came through a different research project with Ontario's Office of the Chief Coroner. That project examined correlations between the COVID-19 pandemic and different mortality rates, and it left Rosenthal with a massive database of unexpected deaths. He saw a chance to run statistics on supposed superstitions.
He said he thought the database was a good record of things people might consider unlucky. He analyzed all recorded unexpected deaths in Ontario between 2009 and 2023. He looked for an uptick in deaths on Friday the 13th, Halloween and full-moon periods. The results were as expected, he said.
The mortality rates were close to the overall rate. He added that it was not that interesting research-wise. Researchers did notice some real patterns. Rosenthal said that over the winter months, including the holiday period, there were elevated deaths because of the challenges of winter in Ontario.
He said that finding was not new to the medical community, but it was an example of detecting genuine patterns in data. The real patterns are more interesting than making up superstition patterns that are not really in the data, he said. He also said there is no scientific explanation for why a particular date would be unlucky. He asked why Friday the 13th would affect all these bad things happening, and said it is just another day.
Rosenthal considers himself evidence that Friday the 13th is not unlucky. He said he has generally had a pretty fortunate life. If he really believed in the superstition, he said, maybe he would have had really bad luck his whole life, but he has not. He is not sure the study will change the opinions of people who hold superstitions.
Superstitions Offer Psychological Comfort to Believers
Superstition brings believers a sense of comfort, he said. He said superstitions illustrate that humans have a need to find reasons for things. It is not enough to say that someone randomly died or randomly won the lottery, he said. It has to be because of some superstition, some good luck charm or some unlucky day, and that gives many people a sense of comfort.
Confirmation bias also plays a role in why superstitions like Friday the 13th persist. He said any time something bad happens on a Friday the 13th, that proves there is truth to the superstition. But if something bad happens on another day, or something good happens on Friday the 13th, people may not notice. He advised considering the evidence behind superstitions.
Confirmation Bias Drives Belief in Unlucky Days
He suggested asking whether there is any scientific logic or whether it is just something built up in the mind, with people noticing patterns even if they are not really there. Rosenthal also recalled a time when he fell prey to superstition. He made a bet with a friend on the outcome of the 2016 U.S. presidential election. He had originally bet that Democratic candidate Hillary Clinton would win.
His friend enticed him to change his answer by offering two-to-one odds. He took the odds, just $1 to $2, and then Trump won, so his friend had to pay him $2. He said he got a weird feeling that maybe it was because he made the bet, and maybe that somehow had an effect on the election. He acknowledged the feeling did not make sense logically, but it struck home for him as to why people believe superstitions.
You find yourself thinking that way, that there are these magic connections, he said.
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CTVToronto:This story was compiled and edited by the HeadTopics newsroom and HT AI from the reports above.
Friday The 13Th Superstition Ontario Death Rates Study Jeffrey Rosenthal Statistics University Of Toronto Research Confirmation Bias And Superstition
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