All snowflakes are unique: comments on ‘What every teacher needs to know about psychology’ (David Didau & Nick Rose)

This book and I didn’t get off to a good start. The first sentence of Part 1 (Learning and Thinking) raised a couple of red flags: “Learning and thinking are terms that are used carelessly in education.” The second sentence raised another one: “If we are to discuss the psychology of learning then it makes sense to begin with precise definitions.”   I’ll get back to the red flags later.

Undeterred, I pressed on, and I’m glad I did. Apart from the red flags and a few quibbles, I thought the rest of the book was great.  The scope is wide and the research is up-to-date but set in historical context. The three parts – Learning and Thinking, Motivation and Behaviour, and Controversies – provide a comprehensive introduction to psychology for teachers or, for that matter, anyone else. Each of the 26 chapters is short, clearly focussed, has a summary “what every teacher needs to know about…”, and is well-referenced.   The voice is right too; David Didau and Nick Rose have provided a psychology-for-beginners, written for grown-ups.

The quibbles? References that were in the text but not in the references section, or vice versa. A rather basic index. And I couldn’t make sense of the example on p.193 about energy conservation, until it dawned on me that a ‘re’ was missing from ‘reuse’. All easily addressed in a second edition, which this book deserves. A bigger quibble was the underlying conceptual framework adopted by the authors. This is where the red flags come in.

The authors are clear about why they’ve written the book and what they hope it will achieve. What they are less clear about is the implicit assumptions they make as a result of their underlying conceptual framework. I want to look at three implicit assumptions about; precise definitions, the school population and psychological theory.

precise definitions

The first two sentences of Part 1 are;

Learning and thinking are terms that are used carelessly in education. If we are to discuss the psychology of learning then it makes sense to begin with precise definitions.” (p.14)

What the authors imply (or at least what I inferred) is that there are precise definitions of learning and thinking. They reinforce their point by providing some. Now, ‘carelessly’ is a somewhat pejorative term. It might be fair to use it if there is a precise definition of learning and there is a precise definition of thinking, but people just can’t be bothered to use them. But if there isn’t a single precise definition of either…

I’d say terms such as ‘learning’, ‘thinking’, ‘teaching’, ‘education’ etc. (the list is a long one) are used loosely rather than carelessly. ‘Learning’ and ‘thinking’ are constructs that are more complex and fuzzier than say, metres or molar solutions. In marked contrast to the way ‘metre’ and ‘molar solution’ are used, people use ‘learning’ and ‘thinking’ to refer to different things in different contexts.   What they’re referring to is usually made clear by the context. For example, most people would consider it reasonable to talk about “what children learn in schools” even if much of the material taught in schools doesn’t meet Didau and Rose’s criterion of retention, transfer and change (p.14). Similarly, it would be considered fair use of the word ‘thinking’ for someone to say “I was thinking about swimming”, if what they were referring to was pleasant mental images of them floating in the Med, rather than the authors’ definition of a conscious, active, deliberative, cognitive “struggle to get from A to B”.

Clearly, there are situations where context isn’t enough, and a precise definition of terms such as ‘learning’ and ‘thinking’ are required; empirical research is a case in point. And researchers in most knowledge domains (maybe education is an exception) usually address this requirement by stating explicitly how they have used particular terms; “by learning we mean…” or “we use thinking to refer to…”.  Or they avoid the use of umbrella terms entirely. In short, for many terms there isn’t one precise definition. The authors acknowledge this when they refer to “two common usages of the term ‘thinking’”, but still try to come up with one precise definition (p.15).

Why does this matter? It matters because if it’s assumed there is a precise definition for labels representing multi-faceted, multi-component processes, that people use in different ways in different circumstances, a great deal of time can be wasted arguing about what that precise definition is. It would make far more sense simply to be explicit how we’re using the term for a particular purpose, or exactly which facet or component we’re referring to.

Exactly this problem arises in the discussion about restorative justice programmes (p.181). The authors complain that restorative justice programmes are “difficult to define and frequently implemented under a variety of different names…” Those challenges could be avoided by not trying to define restorative justice at all, but by people being explicit about how they use the term – or by using different terms for different programmes.

Another example is ‘zero tolerance’ (p.157). This term is usually used to refer to strict, inflexible sanctions applied in response to even the most minor infringements of rules; the authors cite as examples schools using ‘no excuses’ policies. However, zero tolerance is also associated with the broken windows theory of crime (Wilson & Kelling, 1982); that if minor misdemeanours are overlooked, antisocial behaviour will escalate. The broken windows theory does not advocate strict, inflexible sanctions for minor infringements, but rather a range of preventative measures and proportionate sanctions to avoid escalation. Historically, evidence for the effectiveness of both approaches is mixed, so the authors are right to be cautious in their conclusions.

What I want to emphasise is that there isn’t a single precise definition of learning, thinking, restorative justice, zero tolerance, or many other terms used in the education system, so trying to develop one is like trying define apples-and-oranges. To avoid going down that path, we simply need to be explicit about what we’re actually talking about. As Didau and Rose themselves point out “simply lumping things together and giving them the same name doesn’t actually make them the same” (p.266).

all snowflakes are unique

Another implicit assumption emerges in chapter 25, about individual differences;

Although it’s true that all snowflakes are unique, this tells us nothing about how to build a snowman or design a better snowplough. For all their individuality, useful applications depend on the underlying physical and chemical similarities of snowflakes. The same applies to teaching children. Of course all children are unique…however, for all their individuality and any application of psychology to teaching is typically best informed by understanding the underlying similarities in the way children learn and develop, rather than trying to apply ill-fitting labels to define their differences. (p. 254)

For me, this analogy begged the question of what the authors see as the purpose of education, and completely ignores the nomothetic/idiographic (tendency to generalise vs tendency to specify) tension that’s been a challenge for psychology since its inception. It’s true that education contributes to building communities of individuals who have many similarities, but our evolution as a species, and our success at colonising such a wide range of environments hinges on our differences. And the purpose of education doesn’t stop at the community level. It’s also about the education of individuals; this is recognised in the 1996 Education Act (borrowing from the 1944 Education Act), which expects a child’s education to be suitable to them as an individual.  For the simple reason that if it isn’t suitable, it won’t be effective.  Children are people who are part of communities, not units to be built into an edifice of their teachers’ making, or to be shovelled aside if they get in the way of the education system’s progress.

what’s the big idea?

Another major niggle for me was how the authors evaluate theory. I don’t mean the specific theories tested by the psychological research they cite; that would be beyond the scope of the book. Also, if research has been peer-reviewed and there’s no huge controversy over it, there’s no reason why teachers shouldn’t go ahead and apply the findings. My concern is about the broader psychological theories that frame psychologists’ thinking and influence what research is carried out (or not) and how. Didau and Rose demonstrate they’re capable of evaluating theoretical frameworks, but their evaluation looked a bit uneven to me.

For example, they note “there are many questions” relating to Jean Piaget’s theory of cognitive development (pp.221-223), but BF Skinner’s behaviourist model (pp.152-155) has been “much misunderstood, and often unfairly maligned”. Both observations are true, but because there are pros and cons to each of the theories, I felt the authors’ biases were showing. And David Geary’s somewhat speculative model of biologically primary and secondary knowledge and ability, is cited uncritically at least a dozen times, overlooking the controversy surrounding two of its major assumptions –  modularity and intelligence. The authors are up-front about their “admittedly biased view” Continue reading

educating the evolved mind: education

The previous two posts have been about David Geary’s concepts of primary and secondary knowledge and abilities; evolved minds and intelligence.  This post is about how Geary applies his model to education in Educating the Evolved Mind.

There’s something of a mismatch between the cognitive and educational components of Geary’s model.  The cognitive component is a range of biologically determined functions that have evolved over several millennia.  The educational component is a culturally determined education system cobbled together in a somewhat piecemeal and haphazard fashion over the past century or so.

The education system Geary refers to is typical of the schooling systems in developed industrialised nations, and according to his model, focuses on providing students with biologically secondary knowledge and abilities. Geary points out that many students prefer to focus on biologically primary knowledge and abilities such as sports and hanging out with their mates (p.52).   He recognises they might not see the point of what they are expected to learn and might need its importance explained to them in terms of social value (p.56). He suggests ‘low achieving’ students especially might need explicit, teacher driven instruction (p.43).

You’d think, if cognitive functions have been biologically determined through thousands of years of evolution, that it would make sense to adapt the education system to the cognitive functions, rather then the other way round. But Geary doesn’t appear to question the structure of the current US education system at all; he accepts it as a given. I suggest that in the light of how human cognition works, it might be worth taking a step back and re-thinking the education system itself in the light of the following principles:

1.communities need access to expertise

Human beings have been ‘successful’, in evolutionary terms, mainly due to our use of language. Language means it isn’t necessary for each of us to learn everything for ourselves from scratch; we can pass on information to each other verbally. Reading and writing allow knowledge to be transmitted across time and space. The more knowledge we have as individuals and communities, the better our chances of survival and a decent quality of life.

But, although it’s desirable for everyone to be proficient reader and writer and to have an excellent grasp of collective human knowledge, that’s not necessary in order for each of us to have a decent quality of life. What each community needs is a critical mass of people with good knowledge and skills.

Also, human knowledge is now so vast that no one can be an expert on everything; what’s important is that everyone has access to the expertise they need, when and where they need it.  For centuries, communities have facilitated access to expertise by educating and training experts (from carpenters and builders to doctors and lawyers) who can then share their expertise with their communities. and training is not just for school

Prior to the development of mass education systems, most children’s and young people’s education and training would have been integrated into the communities in which they lived. They would understand where their new knowledge and skills fitted into the grand scheme of things and how it would benefit them, their families and others. But schools in mass education systems aren’t integrated into communities. The education system has become its own specialism. Children and young people are withdrawn from their community for many hours to be taught whatever knowledge and skills the education system thinks fit. The idea that good exam results will lead to good jobs is expected to provide sufficient motivation for students to work hard at mastering the school curriculum.  Geary recognises that it doesn’t.

For most of the millennia during which cognitive functions have been developing, children and young people have been actively involved in producing food or making goods, and their education and training was directly related to those tasks. Now it isn’t.  I’m not advocating a return to child labour; what I am advocating is ensuring that what children and young people learn in school is directly and explicitly related to life outside school.

Here’s an example: A highlight of the Chemistry O level course I took many years ago was a visit to the nearby Avon (make-up) factory. Not only did we each get a bag of free samples, but in the course of an afternoon the relevance of all that rote learning of industrial applications, all that dry information about emulsions, fat-soluble dyes, anti-fungal additives etc. suddenly came into sharp focus. In addition, the factory was a major local employer and the Avon distribution network was very familiar to us, so the whole end-to-end process made sense.

What’s commonly referred to as ‘academic’ education – fundamental knowledge about how the world works – is vital for our survival and wellbeing as a species. But knowledge about how the world works is also immensely practical. We need to get children and young people out, into the community, to see how their communities apply knowledge about how the world works, and why it’s important. The increasing emphasis in education in the developed world on paper-and-pencil tests, examination results and college attendance is moving the education system in the opposite direction, away from the practical importance of extensive, robust knowledge to our everyday lives.  And Geary appears to go along with that.

3.(not) evaluating the evidence

Broadly speaking, Geary’s model has obvious uses for teachers.   There’s considerable supporting evidence for a two-phase model of cognition ranging from Fodor’s specialised, stable/general, unstable distinction, to the System 1/System 2 model Daniel Kahnemann describes in Thinking, Fast and Slow. Whether the difference between Geary’s biologically primary and secondary knowledge and abilities is as clear-cut as he claims, is a different matter.

It’s also well established that in order to successfully acquire the knowledge usually taught in schools, children need the specific abilities that are measured by intelligence tests; that’s why the tests were invented in the first place. And there’s considerable supporting evidence for the reliability and predictive validity of intelligence tests. They clearly have useful applications in schools. But it doesn’t follow that what we call intelligence or g (never mind gF or gC) is anything other than a construct created by the intelligence test.

In addition, the fact that there is evidence that supports Geary’s claims doesn’t mean all his claims are true. There might also be considerable contradictory evidence; in the case of Geary’s two-phase model the evidence suggests the divide isn’t as clear-cut as he suggests, and the reification of intelligence has been widely critiqued. Geary mentions the existence of ‘vigorous debate’ but doesn’t go into details and doesn’t evaluate the evidence by actually weighing up the pros and cons.

Geary’s unquestioning acceptance of the concepts of modularity, intelligence and education systems in the developed world, increases the likelihood that teachers will follow suit and simply accept Geary’s model as a given. I’ve seen the concepts of biologically primary and secondary knowledge and abilities, crystallised intelligence (gC) and fluid intelligence (gF), and the idea that students with low gF who struggle with biologically secondary knowledge just need explicit direct instruction, all asserted as if they must be true – presumably because an academic has claimed they are and cited evidence in support.

This absence of evaluation of the evidence is especially disconcerting in anyone who emphasises the importance of teachers becoming research-savvy and developing evidence-based practice, or who posits models like Geary’s in opposition to the status quo. The absence of evaluation is also at odds with the oft cited requirement for students to acquire robust, extensive knowledge about a subject before they can understand, apply, analyse, evaluate or use it creatively. That requirement applies only to school children, it seems.


Fodor, J (1983).  The modularity of mind.  MIT Press.

Geary, D (2007).  Educating the evolved mind: Conceptual foundations for an evolutionary educational psychology, in Educating the evolved mind: Conceptual foundations for an evolutionary educational psychology, JS Carlson & JR Levin (Eds). Information Age Publishing.

Kahneman, D (2012).  Thinking, fast and slow.   Penguin.