I'm Rory Stewart and I grew up wanting to be a hero and I'm still fascinated by the ideas of heroism.

In my new series, I'm taking in the long sweep of history from Achilles to Zelensky and asking, what is a hero?

Simply doing your job, being a decent human being.

A true hero is someone who just kind of shines by

their own light and that light is to be recognised by others. The Long History of Heroism

with me, Rory Stewart. Listen on BBC Sounds. Thanks for downloading this edition of More or less.

This is the version from BBC Radio 4. Here's Tim Harford.

Hello and welcome to More or Less, following the statistical star to a numerical epiphany.

This week, we'll find out why one of our guests from this series brought a suitcase with him to the studio and wouldn't let it leave his side.

And we'll try to decide which is the greatest racehorse of all time.

But first, we're going to turn our attention to a parable about the financial markets,

a parable about an ox.

It's a story that starts with a trip that the British social scientist and statistician

Francis Galton took

to a country fair back in 1906. It's told by James Surawicki, who recounts the story in his book,

The Wisdom of Crowds. As he was walking through the fair that day, he came across this contest,

and the contest was that an ox had been placed on display, and the crowd around the ox was basically placing wagers on the weight of the ox.

So as Galton described it, there was actually a huge crowd there that day.

Something like 800 people actually tried their luck.

And what's important about this crowd, at least from my perspective, is that it was a relatively diverse crowd.

While many of the people in the crowd were butchers and farmers and probably had some skill

in being able to guess the weight of something like an ox, there were also a lot of people in the crowd who were not, at least on the surface, experts

...