You can find a longer version of this thread in my latest substack article:
open.substack.com/pu...
10/10

I also explored other counterintuitive probability puzzles—like the Birthday problem and Monty Hall—with Alex & Emily.
Hear the episode: www.bbc.co.uk/sounds...
Or pick up How to Expect the Unexpected: uk.bookshop.org/list...
9/10

And even in public toilets—middle cubicles can be up to 50% more likely to be chosen than outer ones: doi.org/10.1111/j.14...

Was middle bias affecting the producers’ choices? Hard to say—but it's one of many ways randomness surprises us.
8/10

Similarly, educational psychologists find that students who don’t know the answer tend to pick the middle options:
doi.org/10.1111/j.17...

The same happens in Battleship, on shelves, dropdown menus:
doi.org/10.1177/1745...
7/10

One key bias is middle bias - favouring central options and avoiding extremes.
Behavioural scientists have shown that adding an 'ultra‑premium' option to an initial offering of 'premium' and 'basic' makes the premium option (now middle) more popular
doi.org/10.1086/208899
6/10

We’re bad at spotting randomness, but also bad at being random. Ideally answers A/B/C should be chosen with equal probability.
Any systematic bias lets sharp listeners like Griffith pick up patterns and beat the 1/3 odds.
5/10

While I can’t speak for the producers (they explain their reasoning on the programme), it seemed to me the issue was our species’ difficulty with randomness.
A major theme of my second book How to Expect the Unexpected:
uk.bookshop.org/p/bo...
4/10

They wanted to answer a question from Griffith in Ghana about Unexpected Elements (www.bbc.co.uk/progra...).
He’d noticed the quiz answers were often B or C, but rarely A—and wanted to know why.
3/10

A couple of weeks ago I had the BBC Crowd Science team over - producer Emily Knight & presenter Alex Lethbridge - to talk about probability in all its surprising forms.
We ended up diving deep into patterns, biases, and randomness itself.
Listen here: www.bbc.co.uk/sounds...
2/10

Cool. I hope you enjoyed it. I went last night and had a great time.

Thanks Laura.

Spot on.

Yep, good work.