Are You a Fox or a Hedgehog?

Some people use grand theories to predict or forecast. Others use evidence and probabilities. Where do you fall?

The fox knows many things; the hedgehog one great thing. —Archilochus.

Philosopher Isaiah Berlin expanded on Archilochus’s insight In the twentieth century. Then, socio-political forecaster Philip Tetlock turned it into a research program called the Good Judgement Project.

As Tetlock sees matters, Hedgehogs have one big theory or predictive model. They're happy to apply this grand theory in most contexts and confidently express their views. But the Foxes are different.

Foxes are skeptical of grand theories and tend to be more modest and tentative with their forecasts. Foxes are ready to adjust their ideas based on feedback from the world.

While no one always predicts with 100 percent accuracy, Foxes significantly outperform Hedgehogs. Tetlock finds that Hedgehogs are particularly bad at long-term forecasting despite their extensive expertise or parsimonious theory. Foxes not only have more accurate predictions but are also more accurate in assigning likelihoods to their predictions, for example, as they assign percentages.

That's not to say that Hedgehogs are never right. The win tends to be highly visible when they are right in their big, far-reaching predictions. These highly visible stopped-clock-twice predictions tend to outshine numerous instances of getting things wrong.

Note that Hedgehogs tend to be partisan or monolithic, while Foxes tend to be equal-opportunity forecasters, often cherry-picking from several different hedgehogs in a manner that will help them adopt what Julia Galef calls a “scout mindset.” Here’s Galef:

It’s what allows you to recognize when you were wrong, to seek out your blind spots, to test your assumptions and change course. It’s what prompts you to honestly ask yourself questions like “Was I at fault in that argument?” or “Is this risk really worth it?” As the physicist Richard Feynman said: “The first rule is that you must not fool yourself – and you are the easiest person to fool.” 

Galef's scout mindset is pretty close to a fox mindset.

Famous Hedgehogs include futurist Ray Kurzweil, who sees most everything through the lens of Moore's Law; economist Paul Krugman, who sees most everything through the lens of Keynesian aggregate spending; and biologist Paul Ehrlich, who views most everything through simple Malthusian overpopulation formulae.

Famous Foxes include economist Bryan Caplan, who is fond of making bets on his predictions and has a remarkable track record for winning those bets; investment guru Charlie Munger, who disciplines himself to destroy his cherished ideas and priors while knowing the 'other side' of an argument as well as those who hold it; and Nicolas Nassim Taleb, who, though he arguably has Hedgehog moments, is known for theories that prepare us to expect the wildly unexpected. 

I'll leave it to you, Dear Reader, to decide whether your humble author is a Fox, a Hedgehog, or something else altogether. I certainly don't speak in granular percentages as Foxes do, and I can be as much a theorist as a Bayesian. Yet, I am almost always deferential to people with local knowledge and skin in the game.

What about you?

One way to improve our collective intelligence might be to find ways to harness each style's best and look for patterns where appropriate. Instead of making too many predictions, try using different predictive lenses. I don't see a priori and a posteriori as incommensurable styles but tools that can work in dynamic interplay.

Indeed, the best forecasters usually know which style fits most for what contexts.