Understanding Probability and Randomness: Tales of Unlikely Coincidences

'Understanding Probability and Randomness: Tales of Unlikely Coincidences'

Introduction

In this podcast, two commentators tell the story of a crazy trial of events that involved two girls named Laura Buxton, a balloon, and their friendship brought together by “fate.” They use this story to further discuss the role statistics plays in life events, more particularly probability and randomness. They share all of the unbelievable similarities between the two girls and have the girls share their testimony of the event as well. Both the girls are named Laura Buxton, they’re about the same age, look similar, they both have the same type of pet, and both live in the same country. Not to mention, the fact that Laura #1 let a balloon go and it found its way to Laura #2 on the other side of the country, which began this series of events. To break down the statistics portion of this situation, the commentators include a man named Jay Koehler, an expert in probability (Koehler, 2010).

The Blade of Grass Perspective

Koehler uses an example called the “blade of grass perspective,” which essentially considers the probability of a certain blade of grass being the one blade a golf ball would land on after being hit. He explains that there has to be a blade of grass that is landed on, so really it isn’t that “magical” that any certain blade was the one. He calls it narrow-minded to think of it being a low probability of a blade being landed on. In the grand scheme of things, it is very likely. He uses this to combat the “incredible amount of fate” that is experienced by the Laura’s story. With human inference and slippery evidence, we seem to see the things that are similar and highlight those things, which is looking only at confirmatory events. He challenges us to look not only at the chance of a single event happening to a single subject, but rather the chance of it happening to the entire sample size (Koehler, 2010).

Personal Reflection on Coincidences

In my personal life, I have only really had one crazy situation that is similar to this, and to this extent. I have a friend with a child named Layken. I have a cousin with a child named Lillian. Both little girls are the exact same age… right to the day. Both names start with an L, they both have an older brother who are the same age, their moms post similar pictures of them on social media, and they both dressed up as a Dalmatian for Halloween last year (and their brother as a firefighter). To make things crazier, they both showed up at the same church fall festival where I was, so it was like déjà vu seeing them both there and looking the same. This to me seemed very unusual, and with each new similarity, it started to get even more strange. My unusual story is very similar to the first story about the Lauras.

Analyzing Perceptions of Randomness

After the podcast interviewees explained more in depth about our perception of randomness and probability, it made me realize that it is not actually that unusual. I am at the age where several friends are having kids around the same time, the babies and each of their brothers were two years apart, which is a common age gap amongst siblings. All moms post the same kind of pictures of their children, and a Dalmatian and firefighter are very common Halloween costumes. This reflection helped me understand the broader implications of probability and how our minds are often drawn to patterns and similarities (Gigerenzer, 2008).

Conclusion

Finally, I live in a small town and the chance of them both being at the same festival isn’t that rare, seeing as it was probably the only community event happening that day. I was so quick to match the similarities that I didn’t think about all the probability of the big picture things being similar. Also, I matched all the similarities they had, but in reality, they share way more differences than similarities. This is what happened with the balloon situation. The similarities were mentioned, but the differences were left out. We found it fascinating because those similarities were capitalized on. In the grand scheme of things, this story was unusual at first, but after it was broken down and explained, it seems less unusual. The podcast effectively illustrates how our perceptions can be skewed and reminds us to consider the full scope of events before drawing conclusions (Kahneman, 2011).

References:

• Gigerenzer, G. (2008). Rationality for Mortals: How People Cope with Uncertainty. Oxford University Press.
• Kahneman, D. (2011). Thinking, Fast and Slow. Farrar, Straus and Giroux.
• Koehler, J. J. (2010). The Base Rate Fallacy in the Lay Interpretation of Probability. Journal of Behavioral Decision Making, 3(3), 169-189.