It’s a beautiful day at the animal Olympics. The national animals are lining up at the starting line, ready to take part in the famous Pisa event. The British bulldog arrives and sits back on its haunches, looking nonchalant. The Singaporean lion is anxiously raring to go. The starting shot is fired, and the animals run, hop, jump and fly along the track, navigating the obstacles to make their way towards the finish line.

For most of the race, Singapore’s lion is in the lead, but as it charges towards the end of the track it is overtaken by Shanghai’s dragon, swooping down from overhead to claim the gold medal. The lion is followed across the line by a pack of East Asian animals, with Finland’s bear, Estonia’s swallow and Canada’s beaver among them. Coming up behind, in the middle of the next pack, is the British bulldog, head still held high, who trots over just after our Kiwi friend.

The trainers in the stands aren’t so complacent, however. This isn’t only a matter of national pride - this race is designed to test the kinds of obstacles their national animals will meet in the real world…

Disappointingly average

OK, I admit defeat: I will need to break out of the analogy at this point. You’ll have heard of Pisa (the Programme for International Student Assessment) - problem-solving tests in maths, reading and science that a sample of 15-year-olds in participating countries take every three years. The UK has historically performed at a disappointingly average standard, with approximately one in five children not reaching the levels in reading and maths that are considered to be essential for full participation in society.

You might think this is fairly arbitrary, but I’ve seen the kinds of questions these students can’t answer, and they really are basic: “Helen rode 4km in the first 10 minutes and then 2km in the next 5 minutes. In the first 10 minutes, was Helen’s speed greater, the same, or less than in the following 5 minutes?”

A sensible reaction to this problem of underperformance is to look to the countries where a much higher proportion of children have mastered these questions to see what we can learn from them. But, unfortunately, the lazy way this has been done has turned many people against such a project altogether.

The worst approach (bar ignoring international evidence altogether - see the Green Paper on grammar schools) is to select a single policy feature of a single top-performing country and copy it wholesale. For example, “Well, Finland does X, so we should, too”.

I’m sure I don’t need to convince you of the futility of this approach, so let’s move on to one that is more forgivable - seeking “natural laws of education”. This is the attempt to look for a single policy that has the same positive effect on outcomes wherever it is introduced. Magic policy + education system = top results. It is the headline that says small class sizes are the answer, or the White Paper that claims we need “strong accountability’ in schools because that’s what all “top-performing” systems are doing. But to seek silver bullets inevitably leads to disappointment when an attempt is made to put the theory into practice.

It is seriously misleading to base policy on headline findings

A paper released by the Education Development Trust late last year details the education systems of five “interesting cities” that have shown rapid improvement in a short space of time: London, Ho Chi Minh, Rio de Janeiro, New York and Dubai. Some key themes emerged as having played a part in several of the cities’ education journeys, but the authors concluded: “It can be seriously misleading simply to base policy on headline findings relating to the effectiveness of single policies reviewed in isolation.”

Let’s make this lesson more visible by returning to the dilemma faced by the trainers of our British bulldog. To improve performance, we could selectively breed them to enhance certain features, and we could carry out artificial organ transplants in the dogs that are chosen to compete (no robo-dogs were created in the writing of this article). To decide what to enhance or implant, we could attempt to find a single feature - long legs, spongy lungs, pointy nose - common to the animals who performed better than us, but not those who performed worse than us, and then create this in our dog.

This would bring only limited success, but it is the approach taken by people who observe a correlation between certain features of education systems and results and take it as a mandate for reform, or by those who see no such correlation and so claim these features are therefore irrelevant. To seek education laws is a fool’s errand. Learning from other systems shouldn’t be like physics - it should be more like biology.

Why as well as what

Correlations are very useful to help us identify what to investigate, but they are just the first step. To improve our bulldog in a way that helps the breed to perform well in the race, it makes sense to look at the “why” as well as the “what”.

If all the winning animals had big hearts, I’d want to study them to discover whether this allowed them to pump more blood around their body relative to their size, or whether these bigger hearts were just a function of them being bigger animals with longer legs. I’d also want to study the broader biological functioning of the animals that did well, and how different biological systems worked together; a high-capacity dragon heart would be no good in our bulldog unless it had the lungs to match.

We’ve moved from physics to biology, but I want to finish by taking us one step further and suggesting that studying education systems is even more complex than this. When studying biology, we can objectively discover how biological systems interact. When studying education, we have to be mindful that ideas themselves can change what goes on in a system.

In Japan, teachers’ belief that all students are capable of succeeding is similar to Carol Dweck’s “growth mindset”, which has been shown to improve students’ efforts. And here in the UK, it is the nation’s understanding and desires around grammar schools - irrespective of evidence about their effect on social mobility - that will determine whether or not they are allowed to expand in England.

Rather than ignoring evidence from abroad altogether, let’s approach it with a little more nuance. We shouldn’t be afraid of complexity. Not all good ideas fit into a tweet.

Lucy Crehan is an international education consultant at the Education Development Trust, and author of Cleverlands: the secrets behind the success of the world’s education superpowers, which will be published on 1 December by Penguin