“Well, they behave fine for me...” are the words that no teacher wants to hear. A smug colleague has an approach that is eluding you and is happier to offer smugness than help. Into the same bucket of sins, we can throw hoarders - the teachers who have files full of fabulous resources that they absolutely won’t let anyone else share - and hermits, who are rarely seen in the staffroom and manage to go for days barely speaking to colleagues.

They say that it takes a village to raise a child, but teaching can sometimes feel quite the opposite of a collective endeavour. It’s remarkable how many people can work in schools full of hundreds of pupils and adults but feel completely isolated and alone. Or how many schools share a town and a community but don’t share ideas and practice.

To paraphrase US president Ronald Reagan’s memorable address to Soviet leader Mikhail Gorbachev, “We welcome change and openness. If you seek prosperity…open this gate, tear down this wall!”

Teaching is far too hard to do alone. Children’s needs are too complex, subjects are too detailed, learning problems are too knotty for any one person to deal with by yourself. As the African proverb goes: “If you want to go fast, go alone; if you want to go far, go together.”

There’s a mountain of research to support the idea that it takes teamwork and collective expertise to make schools successful. A 2011 meta-analysis found that teachers’ sense of “collective efficacy” was strongly correlated to student achievement. A 2014 study found that teacher collective problem-solving and mutual trust and respect were all strongly associated with teachers becoming more effective over time.

However, simply asking teachers to collaborate is insufficient. Too many teachers have experienced long meetings that achieve nothing or really interesting meetings that don’t actually result in any change. We’ve met many teachers who gradually withdraw from joint activity after they learned that they didn’t really have any autonomy and that the meetings were only really about receiving and acting on instructions from senior leaders - how enthusiastic would you feel if you were told “we’ve given you an hour to discuss how enthusiastic you are about our new policy”?

So, what does work?

Trust and teamwork can’t be imposed, they must be grown. Teachers need time to meet together in phase or subject teams to discuss real teaching challenges, looking at student work together and collaborating to evaluate the success of teaching approaches. Leaders need to demonstrate a commitment to solving problems with collective ingenuity, not always imposing ideas from upon high.

Schools need to tap into external expertise - it’s simply not good enough to only share the best ideas within a school; teachers need access to the best ideas in our profession. School leaders need to prioritise CPD budgets and ensure that teachers have the time and resource to access specialist networks, experts, and literature to glean the best ideas. Let’s put an end to schools that mistakenly claim that ‘we’re doing everything in-house as it’s so much better’.

Collective expertise is a central idea for the best organisations - we need to make it an entitlement that every pupil is taught with the best wisdom of our profession, not just the best ideas of the person that happens to be in the room.

Bridget Clay is head of programme (Leading Together) at Teach First. She tweets @bridget89ec. David Weston is the CEO of the Teacher Development Trust. He tweets @informed_edu

Find out more by clicking here and look out for their forthcoming book, Unleashing Great Teaching, to be released in May 2018.