Hedgehogs and foxes

There is a fragment of wisdom that is often attributed to the Ancient Greek poet Archilochus:

“The fox knows many things, but the hedgehog knows one big thing.”

Writing in his essay on Leo Tolstoy, The Hedgehog and the Fox, Isaiah Berlin (pictured) expands Archilochus’ passage into a broad concept of two types of thinkers:

“There exists a great chasm between those, on one side, who relate everything to a single central vision, one system, less or more coherent or articulate, in terms of which they understand, think and feel – a single, universal, organising principle in terms of which alone all that they are and say has significance – and, on the other side, those who pursue many ends, often unrelated and even contradictory, connected, if at all, only in some de facto way, for some psychological or physiological cause, related to no moral or aesthetic principle.”

In The Signal and the Noise, the statistician Nate Silver expanded on this again, and gave some illuminating examples:

“Unless you are a fan of Tolstoy—or of flowery prose—you’ll have no particular reason to read Berlin’s essay. But the basic idea is that writers and thinkers can be divided into two broad categories:

  • Hedgehogs are type A personalities who believe in Big Ideas—in governing principles about the world that behave as though they were physical laws and undergird virtually every interaction in society. Think Karl Marx and class struggle, or Sigmund Freud and the unconscious. Or Malcolm Gladwell and the “tipping point.”
  • Foxes, on the other hand, are scrappy creatures who believe in a plethora of little ideas and in taking a multitude of approaches toward a problem. They tend to be more tolerant of nuance, uncertainty, complexity, and dissenting opinion. If hedgehogs are hunters, always looking out for the big kill, then foxes are gatherers.

Hedgehogs believe in a single, neat, unified approach. Foxes believe in many, messy, disparate approaches.

Or as Karl Weick might put it, hedgehogs and foxes are specialists and generalists.

Generalists and specialists

The following extract is from a paper by the University of Michigan psychologist, Karl Weick, titled “Theory Building as Disciplined Imagination” (Academy of Management Review, 1989).

“Generalists, people with moderately strong attachments to many ideas, should be hard to interrupt, and once interrupted, should have weaker, shorter negative reactions since they have alternative paths to realize their plans. Specialists, people with stronger attachments to fewer ideas, should be easier to interrupt, and once interrupted, should have stronger, more sustained negative reactions because they have fewer alternative pathways to realize their plans. Generalists should be the the upbeat, positive people in the profession while specialists should be their grouchy, negative counterparts.”


This reminds me of Tim Brown and Ideo’s articulation of T-shaped people.

The concept defines two axes of knowledge: breadth and depth.

  • Horizontal people have broad but shallow knowledge. They know a little about a lot. In Weick’s terms, these are generalists.
  • Vertical people have narrow but deep knowledge. They know a lot about a little. In Weick’s terms, these are specialists.

Weick’s insight is that because specialists have invested a lot of time in a narrow field, they form strong attachments to their beliefs and react negatively when presented with new information that contradicts it.

Conversely, generalists have invested their time and effort across a number of fields and thus are more open to new, contradictory information.

When recruiting, Tim Brown looks for evidence of T-shaped people, that is, people with an expertise in one field as well as a deep curiosity in other fields.

Specialising helps them understand their field deeper.

Generalising keeps them open to new information, even if it doesn’t support their beliefs.

Being a generalist makes you better at being a specialist.

It stops you getting too attached.

It stops you from overvaluing the confirmatory and undervaluing the contradictory.

It helps to avoid the confirmation bias.

It opens them up to the idea of new information.

Karl Popper took the idea of generalising one step further.

He teaches us to not only be open to new ideas but to seek them out.
To actively pursue information that disproves our currently beliefs.

This, he argues, is the fastest way to getting to an empirical truth.

Socrates agreed.