The classroom as a cultural ratchet

Every teacher has experienced the joy when a class finally “gets” something, not just in the moment, but in a way that endures and becomes the springboard for the next idea. This kind of cumulative learning is one of the defining features of what it means to learn as a human being.

Across our species, knowledge does not simply spread. It accumulates. It stacks, refines, and upgrades with iteration. In evolutionary terms, this is often described as the ratchet effect: one generation inherits what the previous generation achieved, with relatively little “slip back”, and then adds something new. 

School exists because we are the kind of creatures for whom ratcheting is possible.

Two strands of research help explain why, and they point directly at what great teaching is actually doing.

Why humans ratchet, and other primates mostly do not

Among others, Claudio Tennie, Josep Call and Michael Tomasello argue that many animal traditions (including chimpanzee traditions) sit within a “zone of latent solutions”. These behaviours are things individuals can typically reinvent for themselves if conditions are right, even if they sometimes spread socially. The copying is often product-oriented: “I see what you achieved, I will get the same outcome my way.” 

Humans, in contrast, are much more likely to copy process, not just product. We tune in to the means as well as the ends.  What gets transmitted therefore has higher fidelity, and that fidelity is what makes genuine accumulation possible.

Humans do engage with copying, but we also cooperate in ways that strengthen the ratchet, especially through:

• Active teaching (adults have the proximate goal that children learn, and will adjust to make it happen) 
• Social imitation and conformity motives (copying not only to succeed, but to be “like us”) 
• Normativity (a sense of “the right way”, including sanctioning or correcting deviations) 

That combination explains why human cultures create improbably complex outcomes over time, rather than repeatedly reinventing a simpler version. 

This is a core insight from the field of anthropology and it is also a defining feature of the successful classroom.

The nine-month miracle, and why it matters for pedagogy

In The Cultural Origins of Human Cognition, Michael Tomasello describes a “social-cognitive revolution” at roughly nine to twelve months, when infants begin coordinating attention with others in a triadic way: child, adult, and shared object or event. This includes gaze following, joint engagement, social referencing, and communicative gestures like pointing. 

From this point, children begin to learn in a distinctive human way: not merely by discovering affordances of objects, but by understanding intentional actions and what things are for in a shared cultural sense. In Tomasello’s framing, children learn the intentional significance of tools, symbols, and practices, and this is what makes cultural learning so powerful. 

There is an obvious implication for teachers: schooling is a formalised engine for joint attention, intentional transmission, and cumulative cultural evolution. When it goes well, teachers are not simply delivering content, they are doing species-defining work.

What this means for teaching, in practical terms

When the classroom is a ratchet, the central question becomes:

How do I increase fidelity of transmission without killing thought?

Here are five teacher strategies that directly support cumulative culture.

1) Teach the process, not only the result

If pupils can arrive at the right answer using idiosyncratic strategies, they may succeed today but the culture of the classroom does not accumulate. Product-only success often fails to ratchet.

What you might do:

• Model your method explicitly, then require students to rehearse the method (not just the answer).
• Use prompts like: “What did I do first? Why that, not something else?”
• Expect pupils to narrate the procedure and the rationale.

This aligns with the human advantage over product-oriented copying: process copying supports accumulation. 

2) Make pedagogy visible, so pupils detect “I am being taught”

Research on the ratchet effect shows that when children detect pedagogy, they assume they are meant to learn something generalisable and not immediately obvious. Adult commitment to “making sure they learn” strengthens transmission.

What you might do:

• Use clear “watch this” moments with deliberate signalling: board positioning, pacing, and verbal framing.
• Separate modelling from practice cleanly, so pupils know when to attend and when to attempt.
• Treat re-explanation as normal engineering rather than moral drama.

3) Use joint attention as a tool, not a background condition

Once children have achieved the developmental milestone of ‘joint attention’, it must become a live classroom mechanism.

What you might do:

• Reduce split attention: one shared object of focus at a time (worked example, diagram, sentence, line of code).
• Use “eyes to this” routines sparingly but decisively.
• Check that “we are seeing the same thing” before demanding inference.

This mirrors Tomasello’s claim that triadic coordination is the launchpad for cultural learning.

4) Harness the social function of imitation, ethically

Humans imitate partly to achieve, but mostly to belong. That social imitation increases conformity and fidelity, strengthening the ratchet. 

What you might do:

• Establish classroom “ways we do things” that are genuinely helpful: how to set out work, how to respond, how to check.
• Use exemplars and live comparisons so the “standard” is visible.
• Build identity around scholarship: “This is how mathematicians read a question” or “This is how historians handle sources.”

5) Create norms that protect knowledge, but do not confuse norms with truth

The ratchet effect emphasises normativity: children quickly treat demonstrated methods as “the right way” and may even correct others for deviating. 

There is both a power and risk to that.

What you might do:

• Be precise about what is conventional and what is necessary, for example
• Conventional: layout, notation choices, agreed language.
• Necessary: logical validity, mathematical equivalence, evidential sufficiency.
• When allowing alternative methods, label them explicitly as valid variants so the norm does not harden into dogma.

A final thought: your classroom is a knowledge factory that can compound

What distinguishes humans is not just individual cleverness, but the ability to inherit, stabilise, and improve shared practices through teaching, imitation, and norms.   

That is a compelling description of school at its best.

Schooling is so much more than a sequence of lessons. It is a deliberately engineered cumulative culture.

If you want a simple test of whether your classroom is ratcheting: Is what pupils learn today becoming the shared toolset that makes tomorrow easier, faster, and deeper?

If the answer is yes, then you are not just getting through content, you are building a culture that can accumulate and underpin your pupils future contribution to humanity’s success.