Category: Skepticality


(Submitted by Skepticality listener Garrett)

So, recently I was at the gym that I have been going to for the last ten years. This gym is convenient for me because it is about five minutes from where I regularly teach, however it is about 30 miles from my house driving east.

I befriended an acquaintance at the gym, maybe three or four years ago, and we have been getting to know one another little by little. Over the years I have learned many things about Chris – surprisingly that we have the same employer (but never ran into one another because we are in buildings on the opposite side of town – not that weird – a lot of people work there) among other things. I also learned that he lives about 30 miles north of me, but that we share the same supermarket halfway and just never saw one another there either, which would mean that he lives about 30 miles from work as well, albeit on the hypotenuse angle. Little things like that.

Two weeks ago, I was talking with him, and he was describing having a friend in the town I live in. As a matter of fact, he was the godfather of their child who is about three years old – a result of his being in a long term relationship with the uncle of the child, and becoming a very good family friend. Before I told him where I lived specifically, he describes how he gets to their house for perspective – it is the same exit, the same turns, and the same street as me.  As a matter of fact, it is my next door neighbor.

But that isn’t the strange coincidence.

The strange coincidence is that we are very good friends with these neighbors, and my son loves playing with their three children. My wife lets me sit out the children’s parties out of compassion for my sanity…  But it turns out that at all of the family gatherings, she has befriended the exact same acquaintance and has known him for years just as I have. Furthermore, we have told one another anecdotes about him, without ever mentioning him by name even though he has a very common one, and told one another that we should meet him and would get a real kick out of him!  We have had the same acquaintance for years, from completely different circumstances, and didn’t even know it!

Imagine his what his surprise would have been running into our family at the supermarket on a grocery run?

What are the odds of a married couple having a long term acquaintance in two different contexts, especially when a 90 mile perimeter triangle of geography is involved??


Below are the extended notes provided by cognitive psychologist and statistician Barbara Drescher for use in Skepticality Episode 229.  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.

It’s impossible to calculate the odds of this, given the number of variables involved. This is really fun story, and it is a shame that I have to ruin these great stories by focusing on what makes them less interesting, but that’s my job, so here goes:  There is one very important fact that makes this story much less “impressive” probablistically-speaking, and that’s the fact that similarity is attractive. We tend to like people we share interests, qualities, values, and identities with, and when we discover commonalities, the bonds grow stronger.

So, a married couple befriending (and liking) the same person is highly likely. That leaves only the coincidence that they both met this man years ago in situations which are likely to repeat opportunities for bonding. The conjunction of those events is clearly attached to a low probability, but not astronomical.

The Isolated Artist

(Submitted by blog reader Rick Stromoski)

In 1989 my wife and I moved to Connecticut from Los Angeles due to a job offer for her that we couldn’t refuse.

I was and currently am a free lance cartoonist who has always worked from home so it tends to be an isolated existence to begin with. To alleviate the feeling of stir craziness I would occasionally take classes with the idea of getting out of my studio but also possibly learn something new.

I enrolled in a night Illustration class at Central Connecticut University and the instructor’s name was Dana Schrieber. When taking attendance for the first time he came across my name and hesitated. He asked if I had a brother Robert who lived in Los Angeles and I answered in the affirmative. He then told me that he once owned a small gallery in Los Angeles and represented my brother Bobby’s work in the early 1970s . An interesting coincidence given that it was over 15 years and 3,000 miles and we met on the whim that I’d take a night class and he was the instructor. The class ended and that was the last I’d seen of Mr. Schreiber.

Fast forward to the year 2011. My then 16 year old daughter Molly was a junior attending a prep school in Northern Connecticut and met a boy and they started dating. We liked the young man very much and soon we were making plans to meet his mother and her steady boyfriend over dinner. Turns out when we arrived at the young man’s house the steady boyfriend was none other than the same Dana Schreiber who taught that illustration class I’d taken back in 1989. We were all amused at the coincidence but it also afforded me the opportunity to complain about the “B” he gave me for the class.

_____________________________________________________________________________

Below are the extended notes provided by cognitive psychologist and statistician Barbara Drescher for use in Skepticality Episode 228. 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 story is adorable. I can’t think of all that much to say about it that’s interesting, but there are the usual culprits. We tend to forget that factors such as an interest or occupation (in this case, art) increases the probability of running into people who know the people we know. There is also the fact that if it was a friend and not a brother, the author may never have discovered that the teacher was connected because the teacher wouldn’t have recognized his name. Think about how many times that has probably happened in your own life.

In general, we all tend to share interests and values with our family members, the people we work with, and the people we call friends. We are more like those people than we are like random strangers. And those interests and values attract us to others. So, people tend to “cluster”, even if those clusters are large.

(Submitted by friend of the blog Emery Emery)

Local News

SAN CLEMENTE, Calif. – Marion Shurtleff believes in miracles.

In December, the 75-year-old San Clemente, Calif., resident found a piece of her childhood from Covington, Ky., tucked in the pages of a used Bible she purchased at a bookstore near her home.

“I opened the Bible and there was my name,” Shurtleff said in a phone interview from her home. “I recognized my handwriting. I was shaking, literally. I was crying.”

What Shurtleff found was an essay she wrote for her Covington Girl Scout troop when she was 10-years-old.

“It’s three pages, almost four. This was the requirement for the foot traveler badge.”

Shurtleff remembers going to Girl Scouts on Fridays while she attended Fourth District Elementary in Covington. She would go on to graduate from Holmes High School before moving to California for the first time in 1963.

In the essay, she found a detailed account her 10-year-old self gave of a day’s hike through the city that included a meeting of her troop at Trinity Episcopal Church on Madison Avenue.

“We left at 10 in the morning. We went to Devou Park and went around where we had camped the prior year. We walked back to the church and then I took a streetcar home about 4 in the afternoon,” Shurtleff said, summarizing her trip.

Her favorite part of the whole letter she said, was an editorial comment she left in a brief paragraph.

“’We were well provisioned,’” Shurtleff read from the letter. She goes on to describe how each member of the troop had a compass, lunch, and backpack.

“All my friends laughed, and said, yes Marion, that’s you, well provisioned.”

Shurtleff said there was no other clue as to how the Bible carrying her letter ended up in California. The only clue on the letter itself was the name, “Bonnie Gene Edwards,” who she believes was an assistant at her school.

Besides the letter, Shurtleff said she was surprised by the attention she’s received since her story originally ran in the Orange County Register. A local television station, CBS 2 picked up on it and then the Internet.

“I was surprised when the church secretary sent me the email saying it made it to Yahoo,” she said.

Since then, a genealogist and church group has attempted to contact her.

Shurtleff said she would like to know the history of the Bible she purchased. She also added she’s heard speculation that perhaps she always had the letter and possibly forgot it

“I’ve moved too many times. I’ve been down to bare bones. That Bible could have been in Timbuktu, or Alaska. I believe it’s God showing His Grace to us and His love, making us aware that there are stranger things that happen.”

________________________________________________________________________________

Below are the extended notes provided by cognitive psychologist and statistician Barbara Drescher for use in Skepticality Episode 227. 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.

I love this story for several reasons. First, let’s talk about the odds of this happening. There are many factors to consider, some of which Wendy suggested, which involve knowing the history of the book itself. The way I see it, the odds of this happening are extremely small in any case, but many times smaller in some cases than others.

Sixty-five years passed between the time Ms. Shurtleff wrote the essay and when she found it in the Bible. I think it’s reasonable to assume that the essay was placed in the Bible, for safekeeping or perhaps as a bookmark, shortly after she wrote it. This would undoubtedly be in Kentucky. But we can only speculate about how the Bible ended up in a bookstore in California, and how that happened is important in determining the odds that Ms. Shurtleff would find it.

The least shocking possibility is that the Bible once belonged to Ms. Shurtleff, it moved with her from Kentucky to California, and she got rid of it at some point afterward. It is reasonable that she simply didn’t recognize it. If that is what happened, the odds that Ms. Shurtleff would choose and buy that particular Bible are much, much higher than if she had never seen that Bible before. We tend to favor the familiar, even if we aren’t aware that something is familiar.

This would still be a shocking story unless Ms. Shurtleff frequents the store where she bought the Bible. In that case I would have to speculate that the Bible was among books that she sold to the store at some point, or to a neighbor, perhaps in a garage sale, who then sold it to the store.

However, after reading the story, what seems most likely to me is that the essay was left behind during a troop meeting at the church and was placed in one of the Bibles there and forgotten. It must then have been purchased by someone who moved to California at some point. This would make the probability of it finding Ms. Shurtleff very, very low and dependent upon the rates of migration from Kentucky to California during those sixty-five years as well as how often Bibles are sold or given away.

But there are two other interesting thoughts I have about this story. One is a question: why was the essay still there after sixty-five years? This suggests that the Bible was rarely used. Then again, it was discarded, unless it was acquired after its owner passed away.

Finally, I have to wonder about Ms. Shurtleff’s explanation for what happened. She is quoted as saying, “I believe it’s God showing His Grace to us and His love, making us aware that there are stranger things that happen.” If God wanted to show Ms. Shurtleff a miracle, why did he choose such a mundane document, a merit badge assignment? Why not a love letter or some other meaningful document?

(Submitted by blog reader Chuck Colht)

A few years (2009?) ago, one of my daughters gave me a mix cd for my birthday. I had just bought a(nother) sports car and she found a bunch of driving songs from the ’60s to current.  It stayed in my cd player but I didn’t listen too often because I generally had the top down and preferred the sound of the wind.

Anyway, this cd moved from car to car as I changed up but got little play. In 2012, I went to the theater to meet my kids and grand kids to see Wreck-It Ralph. On the way, because I left my iPod at home, I fired up the cd and found track 6: Rhianna’s “Shut up and Drive.” I’m more into grunge but I love this song and couldn’t believe I hadn’t noticed it before.

Now for the coincidence. At one point in the movie Vanellope starts racing around a track to what song? “Shut up and Drive.” So the first time I notice a song that’s been at my disposal for 3 years is the day I hear it on the big screen.

Pretty cool no?


Below are the extended notes provided by cognitive psychologist and statistician Barbara Drescher for use in Skepticality Episode 226.  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.

At least a third of the stories submitted to TOMBC involve incidents which are not statistically interesting, but demonstrate the human brain’s amazing ability to make connections. Humans begin making associations the day we are born, connecting dots wherever we can. This process allows us to predict the world around us. Prediction, in turn, allows us to avoid dangers and plan for the future. It is also the first step in understanding cause and effect, which may allow us to control things in the world. So, it shouldn’t be surprising that we often ascribe deeper meaning to the connections we’ve made.

The author of this story demonstrates the power of attention. The fact that he rarely played the CD before is not relevant, but because he was surprised to enjoy the song, he noticed when he heard it again a short time later. In psychology, we call this effect “priming”. Priming refers to the tendency for something we see or hear to increase the probability that we will respond to that same thing, or something similar or related to it, when we are exposed to it again.

However, there is no real coincidence here. The song is quite popular, so it shouldn’t be surprising to hear it in a movie such as “Wreck-It Ralph”. The CD was appropriate to the outing, so it also shouldn’t be surprising that a song (or even two) on the CD would overlap with the soundtrack of the movie.

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.

(Submitted by reader Carolyn Melendez de Lafuente)

As usual, I was late in prepping our tax documents for our accountant to meet the filing deadline.

I filled in all the information I had gleaned from the various support documents, including the letter from our mortgage company indicating how much interest we’d paid on our mortgage.  I completed the three pages, placed one in the scanner to be scanned onto my computer, and placed the other two on top of the scanner.

I then turned away and fiddled with the app on my computer. I heard the sound of falling paper behind me. When I turned around, the two pages that I had placed on top of the scanner were gone. I obviously heard the sound of them falling, so I gathered that they had floated away. SOMEWHERE.

My search began. Behind the garbage bin. In the garbage bin. Across the room. Behind the filing cabinet that the scanner was on top of. Between the filing cabinet and the wall. I WAS STARTING TO PANIC. Then I thought to look in the sliver of space between that filing cabinet and the immediately adjacent filing cabinet. I pushed it away and there were 3 sheets of paper there — the two I had been looking frantically for AND an additional sheet of paper — a tax form that I had filled out for the previous year, which included mortgage interest paid the year before last.

I noticed immediately that the number was WAY off…almost DOUBLE what I had just written on the current documents I was scanning. Then it dawned on me — our mortgage company transferred our mortgage a few months into the year! I had totally forgotten, and included only one mortgage provider’s numbers. If I hadn’t seen that additional sheet of paper, I would have provided an incorrect number to our accountant! I looked up and said thank you to the Universe for the assist. 🙂


Below are the extended notes provided by cognitive psychologist and statistician Barbara Drescher for use in Skepticality Episode 224.  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.

Things always seem more coincidental when we feel that we have averted some harm. I’m reminded of stories about averting disaster, like people who miss a flight that crashes, or those who called in sick to the World Trade Center on 9/11/2001.

The truth is that if they’d gone to work, there’s a good chance they would have gotten out alive (a majority of people working in the building did).  We forget all of the times that we missed a flight that did not crash or called in sick and nothing happened.

In this case, the chances are excellent that the mistake would have been caught regardless, but the urge to attribute the incident to “fate” is strong.

One Word: Coincidence

(Submitted by reader Bernhard Liefting)

About 10 years ago, I worked in Germany for a few months (I live in the Netherlands) and I spent weekdays in a hotel. One day I picked up a magazine from the hotel lobby to read in my room.

There was an article in there about the plastic industry, titled “One word, plastics”, a famous quote from the movie “The Graduate”, starring Dustin Hoffman, in which the character he plays is given career advice by his uncle.

After a few minutes, I put down the magazine, and switched on the TV, having no clue what was on. What do I see: the movie “The Graduate”, and which specific scene, well, you probably guessed it, the first thing I hear was “One word, plastics”.


Below are the extended notes provided by cognitive psychologist and statistician Barbara Drescher for use in Skepticality Episode 223.  Take a look and leave your comments below. Please be sure to listen to the podcast for our own sarcastic and hilarious commentary. Also, visit Barbara’s blog.

There is no way to quantify this. We’ve had stories like this before, though, so I know that I’ve commented on it.

Things like this happen all the time. For example, last night we were watching “Raising Hope” and Damon said something to the boys about how he wishes they were old enough to see Garret Dillahunt (plays Burt Chance) in “Deadwood”, in which he played two different characters.

A couple of minutes later, Burt (the character) uttered a line from “Deadwood”.

The Cable Coincidence

(Submitted by reader Andy Harding)

We had just moved into a new house and couldn’t find the cable to connect my printer to my computer. I gave up looking and decided to go into town and buy a new one.

As I left the house I found the cable I needed laying in the road. The weekly garbage truck had passed a few minutes earlier.

No, it wasn’t the cable I had lost; it was shorter and a different color. I later found the missing cable in a different box.

When I tell people about this I get some funny looks, I don’t think anyone believes me.


Below are the extended notes provided by cognitive psychologist and statistician Barbara Drescher for use in Skepticality Episode 221.  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 a very impressive story, but I have little analysis to offer.

It’s highly likely that the cable is very common, since most printer cables are pretty standard, but it’s not very often that people just throw out cables. To top that off, how often do those cables fall out of trash bins (or a car, or wherever it came from) to be found lying on the ground? And right when he needed it?

I’d say this one is just one of those extremely unlikely events that we must expect a few of in our lives.

(Submitted by blog reader Tom B.)

In 1999/2000 and I was living and working in Cambridge, my mum knowing I liked sci-fi and fantasy had posted me an old book she had found on a holiday to Brighton, the book was an anthology called Strange Adventures in Time.  I had been reading through the book and had got to Rip Van Winkle by Washington Irving (I was reading this book on the loo, and had a CD playing in the next room).

The CD was the first album by my favourite band – Belle and Sebastian called Tigermilk and I had owned it for 2-3 years and listened to it regularly.  While reading the book and listening to the CD in the background I got a weird feeling, and as I sat there contemplating the song “I could be dreaming”.

Now this song has a part where a woman talks in a lovely Scottish accent in the background starting quietly and getting louder, and I had never known or paid much attention to her or known what she was reading. However as I listened and read I noticed that she was reading the words from the page I had just read.  This gave me a weird spooky feeling and I can’t remember a more striking coincidence happening to me, and I’m always reminded of it when I listen to the song.


Below are the extended notes provided by Ed Clint for use in Skepticality Episode 220.  Take a look and leave your comments below. Also, please be sure to listen to the podcast for our own sarcastic and hilarious commentary.

This is my second contribution to the series and I want to take this opportunity to briefly emphasize there are, strictly speaking, statistics can’t apply to singular events. Probability theory is based on sets of things (like a deck of cards), and answering, what can we say about this set when interacting with it? One-of events are by definition, not part of a set. Here on TOMBC we do talk about odds, and rightly so, but we do so in the sense of the folk meaning of “likelihood”. We will talk about numbers, but these are either metaphorical odds expressing a subjective appraisal of likelihood (not statistical odds) or else are the odds of some set of events that resembles in many details the strange one-of coincidences. I expect this point has been made on TOMBC before, but I like to be clear.

It’s plenty freaky to hear the text read aloud on a CD you’ve just read yourself. The first question is, what are the odds any one piece of pop culture, like a song, references or quotes a specific other bit, like a story? Many songs include quoted intact bits of audio, or else quotes or allusions: Information Society sampled Star Trek, Sir Mix-A-Lot sampled Full Metal Jacket, Gwen Stefani sampled The Sound of Music, and the melody from the White Town one-hit wonder Your Woman includes a trumpet riff from the soundtrack of a 1930’s serial also often thought to have been appropriated by George Williams for Star Wars. Wheew! Songs that use appropriated exact quotations are relatively rare. No such data on them exists so far as I know, but let us suppose only one in 5,000 fits the criteria. Now, any one person has not been exposed to all of those (Who the hell is “Information Society”?, I can hear the young-uns asking), perhaps the average music fan has only encountered one in 10 of them. Lastly, what are the chances the listener possesses the quoted media and experiences them both (nearly) simultaneously? For the former, the chances are actually quite high. Having long since passed into the public domain, Rip Van Winkle has been published as a story or as part of a collection many dozens of times. It’s published digitally through many projects such as Project Guttenberg. It appears, in full, on many websites and as the focus of many essays and articles. Let’s say that 50% of literate westerners have read the story. How likely was it for the song to be playing somewhere near to the moment the text was read? If by “often” the writer means once a day on average, and considering the average person listens to 82 songs a day, then assuming said person always has music on while dong light reading, we can estimate the chance at one in 82. That works out to about one in 8.2 million. This seems pretty darn unlikely, but there are some important caveats to think about that diminish the odds in ways that are difficult to calculate:

The odds of encountering a reference to Rip Van Winkle in one or more pieces of pop culture are better than you might think. Winkle is one of the most beloved and enduring pieces of 19th century fiction which is constantly turning up again and being retold. Google turns up 1.25 million hits and Wikipedia lists four songs by separate artists that reference the story. Major media franchises have retold it, including The Flintstones, The Twilight Zone, and of course the animated series Futurama, which is based entirely on the story. This observation increases the odds any artist will feature a reference, as well as the odds you would otherwise come across the references yourself, which brings me to a second caveat.

The odds are improved by what we might call the “clumpiness” of taste, the observation that our tastes do not vary arbitrarily and that we tend to like clumps of similar creative media. The reason you are listening to Belle & Sebastian five times this week is that you share some aspects of taste with those artists. It stands to reason the band and you might like these stories for the same reason, which is also part of the reason you’re listening to their disc on repeat to begin with. Web 2.0 media services like Netflix and Pandora produce recommendations based on such clumpiness of taste, and not without some success. One critic called the band’s work “wistful pop”, and perhaps not-so-coincidentally Van Winkle is a story rooted in dismay over the ugly necessity of the American Revolution. A wistful story, indeed.

____________________________________________________________________________________________

Edward Clint produces the Skeptic Ink Network and writes about Evolutionary Psychology, critical thinking and more at his blog Incredulous. He is a bioanthropology graduate student at UCLA studying evolutionary psychology.

Kidney compatibility

(Submitted by blog reader David Read)

About 9 months ago, my wife learned that she might need a kidney transplant. For most of her life she has endured reduced kidney function due to several infections suffered while she was a teenager. But in September, she learned that her kidney function (GFR) had dropped to 13 (out of 100). Usually, when someone’s GFR falls below 15, they become a transplant candidate. With this precipitous drop in function (her previous GFR had been in the 30’s), we thought we had only a few weeks before she would need to start dialysis.

We attended several day-long classes in which we learned about  the different types of dialysis and to get an understanding of the transplant process (getting on “the list”, looking for a living donor, awaiting a cadaver donor, etc). We learned that if we waited for a cadaver donor, it could be up to 7 years before she would make it to the top of the list and then would have to wait for a matched donor kidney to become available. Obviously, the solution would be to find a live (and willing) donor. In the class we learned that the best chance of finding a match would be with a sibling. Luckily, my wife has 2 – a brother and a sister.

The process of “matching” is fairly straightforward. First, the donor has to be the same blood type, in this case O. The Rh factor is not important. After the blood type is matched, samples of the donor’s and recipient’s blood are drawn and compared. There are 6 antigens that can determine whether a donated kidney will be accepted or not. A perfect match is when all 6 are compatible.

My wife’s siblings agreed to be tested but neither of them even knew their blood type. Surprisingly, neither did their doctors! My wife and I know our types because we have given blood and the Red Cross lets you know your type. We suggested that her sibs donate a pint of blood to 1) do a good deed and 2) learn their blood type for free. After much hand wringing and delays, we learned that both her sibs had blood type A – neither were a donor candidate.

In the meantime, our daughter determined that she was type O and she and my wife went in together to test for a match. During the matching process, only the donor is given the results. This is to protect the donor from any extra pressure from family members or the recipient. For instance, if after finding that they are a match a donor has a change of heart (no pun intended), they are the only ones who know that they matched in the first place. However, when our daughter received the news that she matched, she was ecstatic and called her mom right away.  She really wanted to be the one who helped her mom through this crisis.  However, there was one more hurtle to be cleared – the ultrasound.

After a match is found, the donor must undergo an ultrasound to determine the health, location and number of kidneys (yes, some people are born with one kidney, and some even with three!). Our daughter’s ultrasound results were devastating – for her. She had kidney stones and therefore could not be a donor. On the positive side, she learned of this issue long before it became a problem and has taken care of it. But, that didn’t help my wife.

However, our son-in-law decided that if his wife couldn’t donate, perhaps he could. After determining that he had the correct blood type , he went in for the compatibility tests. This was quite a decision for him because he has an aversion to seeing his own blood and these compatibility tests require that 6 – 8 vials of blood be drawn. But when the results came back – he was a match also! And the ultrasound found no irregularities. So the question is, what are the odds of BOTH a child AND their spouse being a matched kidney donor for a parent?


Below are the extended notes provided by cognitive psychologist and statistician Barbara Drescher for use in Skepticality Episode 218.  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.

First, there is a sticky problem of the probability that any donor will be healthy enough. I could not find a criterion or probability value for that, so I will have to leave it out of any calculation.

Second, the author discussed HLA matching as if it was an all-or-none deal according to several sources, including the LivingKidney Donors Network, it is no longer standard practice to use HLA matching as a factor to determine whether a donor is compatible. As it turns out, an exact match is best, but not necessary. Furthermore, there is little statistical difference in the survival rates among recipients with 5/6 and 0/6 matches, thanks to newer, better anti-rejection drugs (yeah science!).

For that reason, unless there is a perfect match, donor compatibility relies on the result of a number of tests of complex cell interactions to determine whether the recipient’s body will reject the organ.This is important, because the rest of what I will say here makes the prospect of finding a kidney donor look like finding Waldo in Santa’s workshop.

All of that said, the author suggested that both the daughter and son-in-law were perfect HLA matches, so we have enough information to at least estimate the odds, assuming that everyone involved is healthy.

The six antigens which have been identified as important for transplant are inherited from our parents, half from each. This makes a sibling the best possible chance for a perfect match, not a child, but a child is better than a stranger.

A perfect match with an unrelated donor carries odds of one in 100,000, or a probability of .00001. Since the daughter received half of hers from her mother, she is at least a 50% match, doubling the probability that she is a perfect match to .00002.So, the probability that both the daughter AND her husband would be “perfect matches” in terms of HLA compatibility is .00001 times .00002, or .00000000002 (5 million to one).