Are you a hedgehog or a fox?
Are you able to deeply focus on one specific activity
such as rolling up in a spiky ball and sleeping through the winter?
Or are you alert to changing circumstances and keep your eyes
and ears open to new threats and opportunities?
My name's David Spiegelhalter, and I'm a statistician and fascinated
by the problems of risk and prediction.
Philosopher Isaiah Berlin wrote a famous essay,
The Hedgehog and the Fox,
after a famous poem by the Greek poet Archilochus who said...
Think of the people you know, either privately or public figures.
Are they hedgehogs,
with one overarching way of looking at the world,
through which they interpret all around them?
Or are they foxes, with no big principles of philosophy,
who muddle along adapting to what turns up
and changing their minds along the way?
Politicians of course tend to be hedgehogs,
but some are more pragmatic and foxy than others.
Now, who would you trust most to make predictions about the future?
A confident hedgehog or an uncertain and vacillating fox?
This was put to the test in a long series of experiments
by political scientist Philip Tetlock, who studied 284 experts
making 28,000 predictions about long term events.
Tetlock was looking at who predicted best.
And mainly it made no difference whether the forecaster was
an optimist or a pessimist, conservative or liberal.
The only consistent pattern was how they thought, not what they thought.
He found that foxes were much better at predicting than were hedgehogs.
And hedgehogs were particularly poor at subjects
at which they were experts.
They were just too confident in their forecasts.
A classic hedgehog was the historian Arnold Toynbee,
who in 1947 was declared TIME magazine's Man of the Year.
Others wrote that he was...
...largely because his great work, A Study of History,
spoke to the biggest fear of the time,
that nuclear weapons were going to end civilisation.
Toynbee made the confident and comforting prediction
that this wouldn’t happen...
because it was an opposition to his self-proclaimed
scientific theory of history.
Toynbee thought that Western civilisation wasn't nearly done yet,
because it hadn't reached the stage of universal government
and a religious renaissance.
All 23 civilisations he had studied had done so before they collapsed,
and so would the West.
He thought the golden age of universal government
and religious observance would start around the year 2000.
His peers were sceptical and they were right.
Today Toynbee is hardly remembered, except perhaps as a classic hedgehog.
In his book, Future Babble,
Dan Gardner identifies three characteristics of good forecasters.
Number one: aggregation.
They use multiple sources of information,
are open to new knowledge and are happy to work in teams.
Number two: metacognition.
They have an insight into how they think and the biases they might have,
such as seeking evidence that simply confirms pre-set ideas.
Number three: humility.
They have a willingness to acknowledge uncertainty,
admit errors and change their minds.
Rather than saying categorically what is going to happen,
they are only prepared to give probabilities for future events.
Acknowledging, in the words of that great sage, Donald Rumsfeld,
both the known unknowns and unknown unknowns.
So when someone is telling you what is in store for you,
the country, the world...
just ask yourself, are they a hedgehog or a fox?