Do crowds really make the best decisions? I found out using scotch

To find out whether the 'wisdom of crowds' is real, I asked people on Twitter to guess the weight of my scotch. With Britons voting in a referendum to leave the EU, their responses speak volumes about the ability of populations to find the right answers

Let me tell you the most boringly overused statistical anecdote ever. In 1906, an ox was butchered at a fair in Plymouth. 800 people present were asked to guess it's weight, and you will literally not be amazed when you hear what happen next. From the Victorian polymath Francis Galton, who wrote about the event, we know that average of the crowd's estimates was within a gnat's bingo wings of the true figure - 1207 pounds versus 1198.

Fast forward about a century, and James Surowiecki popularized the concept of 'the wisdom of crowds' in his book of the same name. The basic idea is this: if you get a large number of people, and you ask them to answer certain types of question - usually ones involving estimation, general knowledge and spatial reasoning - the average of their answers will be as good as or better than any one of them. The theory is that random individual errors cancel each other out, while collectively the crowd acts as a kind of fishing net to gather lots of little bits of information that accumulate to guide the result.