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Numbers that make you go aaahhh

In one of my management modules on my Toulouse year abroad, we were clued up on ‘Dunbar’s number’. It got me thinking, what other numbers have strange significances? So here are a few weird and wonderful numbers that will make you go ‘oooooh’. If they don’t, well this’ll be a waste of time and a darn shame won’t it?

150 (people)

Let’s start with that hairy anthropologist, Robin Dunbar. When we’re in groups we’ve got to juggle our hefty egos, negotiate power and understand internal politics (such as why Laura is blanking Holly).

According to Dunbar, 150 is the maximum number of people with whom we can effectively pursue this social juggling. Beyond this number, we cannot maintain stable relationships. The cracks begin to show as we can’t even remember who Laura is and it all gets a bit messy.

This 150 rule can be applied to anything from friends, to companies and even to the sizes of tribes. Some companies have taken this phenomenon to heart; Gore Tex, for example, always have company divisions of 150 or less. If their employees grow they simply divide the company into more sections and migrate the 150 to another building. Proof of their success? They have been rated one of Americas best-managed companies.

Definitely above 150. Uh oh.

175 (BPM arousal)

In normal situations, our heart rate sits between 60 – 100 bpm. However, in stressful situations, our heart rate increases to boost bloodflow. From 145 to 175bpm, our senses are heightened, minds focused, and we can really perform. Achieve this heart rate and catching that flying piece of toast as it pops will be a piece of cake.

However, above 175 bpm our brain shuts down non-essential functions and we start to make rash decisions. Even simple bowel movements can be disregarded in the wake of extreme fear… better change that underwear, sport.

50,000 (pounds income)

Money doesn’t equal happiness, right? Sorry Corbyn, that might not actually be the case. According to Nobel Prize-winning psychologist Daniel Kahneman, income gains up to £50,000 make people more satisfied and happier in life. However, £50,000 is the threshold for happiness; anything above this and happiness plateaus. This could be slightly biased since the study was competed in America and evidently due to their lack of healthcare there are more associated health costs. Nevertheless the 50,000 figure remains interesting.

According to Dan the man: “Perhaps £50,000 is a threshold beyond which further increases in income no longer improve individuals’ ability to do what matters most to their emotional well-being, such as spending time with people they like, avoiding pain and disease, and enjoying leisure.”

“No danger of that here,” I sobbed back.

23 (birthdays)

If there are just 23 people in a room, there’s a 50/50 chance that two of them will have the same birthday. This interesting phenomenon (birthday paradox) messes with our intuition, as people generally think it would have to be half the number of days of the year for there to be a 50:50 chance.

How many people would need to be in the room for a match to be certain?

Well with 75 people it’s pretty much certain (99.9% chance). As more people enter the room the number of potential combinations skyrockets. A group of five people has 10 possible pairs yet a group of 10 people has 45 different possible pairs. This exponential relationship is difficult to understand because our ickle human brains love a linear relationship. If you’re not satisfied with my primitive teaching, then migrate here.

So there it is comrades, a few peculiar digits to get you thinking. Got any numbers that top these beauties? Try me in the comments.


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