New Year Coincidence, 2015

(Submitted by Skepticality listener  Mark Gouch relayed to The Odds Must Be Crazy by Barbara Drescher.)

Here is the article (includes video) by Barry Wolf, WKYC.

But how can we say this is unbelievable as they do in the article? Sorry, but I can’t help myself here…

The odds would be one out of 365 * 365 * 365, or about one out of 48.6 million births. With 7 billion people on the planet, odds are that this has probably happened about 143 times ( to living persons. many more to those in the past). So rare, fun, and interesting, but not unbelievable.

I believe it happened based on the evidence (their claim that it did, which is good enough).

Actually since everyone has to have a birthday, we can ignore the first birthday, that of the man or the woman. So the odds someone marries someone with the same birthday (date of the year) as them is 1/365.

Then the odds their baby has that same birthday would be 1/(365 * 365) or 1/133,225. So with ~7 billion people this probably happened 52,543 times to persons living on the planet now.

The error in the first calculation is that the date was selected first. That calculation is correct for any specific date, whether it is January 1st or July 4th, or March 15th, or July 22nd. Anyone with better knowlege of probability please correct me if any of the above is incorrect.

As often happens, things that seem unbelievable are quite believable and things that are believed without evidence are not believable.

Below are the extended notes provided by cognitive psychologist and statistician Barbara Drescher for use in Skepticality Episode 246.  Take a look and leave your comments below. Also, please be sure to listen to the podcast for our own hilarious commentary. Also, visit Barbara’s blog.

Good job!

You are correct with both calculations. It depends on how you frame it. If you’re wondering the odds of two people with the birthday of January 1st marrying and having a baby on January 1st, then the first is correct, but as you pointed out, that’s not really what’s interesting.

The only thing I would add is that these calculations also assume some things that we know are not true, such as that births are uniformly distributed across the days of the year. Even if natural births were (they aren’t), we’d see fewer births on days like January 1st simply because the number of scheduled C-sections and inductions is lower because it’s a holiday. However, figuring those few things in requires data that probably isn’t available.

Dreaming and Coincidence

Submitted by a reader who prefers to remain anonymous. From her blog:

“As a follow-up to my last blog “Proof of Life After Death” which explored the possibility of psychic mediums communicating with those who have crossed over…

There are more ways besides mediums that your deceased loved ones can personally communicate with you..to let you know they are well and watching over you. I would like to share with you one…of many signs…that have proved to me that my deceased loved ones still live on. This story is about my beloved Grandmother or as I called her – Nana.

About 10 years ago I was trying to have a 2nd child…my first came easy but the 2nd proved to be difficult. I happened to be staying at my mom’s overnight (where Nana had lived the last few years of her life) and before I went to bed asked Nana to pray for me to have another baby.

That night, THE DREAM happened ..I was asleep but still knew as it was happening that it was TOO REAL to be just a dream… my Nana came to me. The dream was as real to me as you reading this right now.  I was crying, so happy to see my Nana and hugged her and asked her if she was OK …”Good,” was her response…”I can’t stay long,” she said “but want to tell you that you are going to have another baby!” I responded that I knew I was asleep and could she offer me any PROOF that she was really there talking to me. She said, “Remember the slippers. You’ll know it’s me because of the slippers. Remember the slippers.”

When I woke the next morning the “dream” I had the previous night was as clear as day. I remembered her “slippers” message but in the wake of day…slippers.. had NO meaning for me. None. That is, until I finally asked my Mom (without giving her any details about my dream) … “Mom, this is gonna sound crazy but is there anything special you would think of associated with Nana and slippers?”

She immediately said “Yes, I was reading an article in a magazine a few days ago about a daughter who was taking care of her elderly dying mother (as my Mom had taken care of my Nana) and how her dying Mom’s slippers (and the loss of one of them which paralleled her loss of independence) were a major point of the article.” My Mom then told me that the article moved her so much because it reminded her of my Nana that she saved the article for me to read. The title of the article…”The Gray Slippers.”

Welcome, baby Ryan 3-2-04!

Thank you Nana, for being there for me… always.

XO

Below are the extended notes provided by cognitive psychologist and statistician Barbara Drescher for use in Skepticality Episode 225.  Take a look and leave your comments below. Also, please be sure to listen to the podcast for our own sarcastic and hilarious commentary. Also, visit Barbara’s blog.

This is another case of the very human tendencies to find meaning in coincidences and ascribe agency. There are several points to address here.

– Dreams that we can remember are often described as vivid, and we experience (and remember them) as if they are physically real because brain activity while we are dreaming is very similar to brain activity when we are awake. So to say a dream did not feel like a dream is not only not unusual, it’s how most people experience dreams, and when we believe they are meaningful, we’re more likely to share them and thinking about them, construct stronger images to beef up the memory.

– The slippers in the story her mother read are not connected with being pregnant or with anything in the author’s life. They are not even connected with anything in the grandmother’s life or the mother’s life.

– When the author asked her mother if she knew what “slippers” meant, her mother searched her memory for some reference to slippers and came up with the story. This is not at all unusual. In fact, it would be unusual for her to come up with nothing. I would be much more impressed if, for example, the mother arrived at the author’s house with slippers the author wore as a baby. Even if that were the case, it would still be a case of making connections between unrelated things (finding patterns) and assuming that they must be related in a causal way (ascribing agency).

But there is no reason to think that there is anything more than the dream of a woman who was focused on having a child, a woman who looked for greater meaning in that dream.