THIS week, I sat across a Chinese restaurant table from three nine-year-old school girls – out for their Thursday dumplings treat – and just marvelled.

They role-played, oohed over pop stars, rated teachers, rated each other, asked enormous and unanswerable questions, shared daft jokes, performed complex teasing games on their Facetime apps, skipped down the pavement outside with exact synchronisation, then came back in and started all over again.

I brought up two girls in the nineties and noughties but I’d forgotten all this – the energy, the experimentation, the sheer joy in testing out your faculties with your pals.

This was my brother’s school run, his daughter one of the three. To be honest, I was shuddering a little. How do you cope, bro?

“You’ve forgotten that you only have to respond to about half of what’s happening,” he wisely mused. “But yes, they are fab.”

We adults groan and complain mightily about the stresses of modern parenting, the insufficiency of childcare, the anxiety over school test performances. But do we exult enough in the sheer wonder and privilege of being part of the growth of another human being?

As children assemble themselves, their willpower and their interests, they remind us of our own component parts – those that are working well enough, but also those that are functioning poorly, or have fallen out of use. Parenting remains the greatest learning experience of my adult life.

What I’m most grateful to the children in my life for is the way they have confirmed my abiding theme – the power and potential of play. My brother is the most playful of dads. We’ve been in our recording studio all week, but the place is half toys-and-arts store, including a makeshift cinema for Disney watching. Downstairs, a kindergarten’s outside play area explodes and starfishes all day.

It is the most congenial environment in which to pour your heart into your songs.

But it’s the relentless, inescapable nature of play for children that always strikes me most. It simply has to happen, and cannot be stopped. Since my book The Play Ethic in 2004, I’ve become a deep geek for scholarship on play, so I have a good idea of the explanations for this.

The strongest reasons are evolutionary. Play – and not just in humans – happens because we have to rehearse our survival skills. In more complex, thoughtful, bigger-brained animals, these rehearsals are about meeting the emotional and social challenges of others, as well as evading (or becoming) predators.

I see this elemental process right before me, with these three lassies: sussing out what yourself and others can take, but perpetrated in a mood of fun, delight and curiosity. Fun is the reward for this necessary prototyping: how to become a social human.

But the realisation that humans are built for play throughout their whole lives – that we don’t really put “childish things behind us”, but translate them into sports, arts, flirting, invention, entrepreneurship, visions for the future – has always had, for me, political implications. As our societies, cultures and economies become more entangled and complex, doesn’t that imply that we need more time and space to rehearse for all this, rather than less?

One of the most powerful domains of play scholarship comes from neuroscience, and one of the most beautiful ideas is American psychologist Allan Schore’s understanding of play as helping us to “regulate affect”.

By affect, Schore means all the ways that we trigger each other reactively and involuntarily, around core survival emotions (such as fear, rage, sadness, care, play, curiosity, lust).

Rich play experiences, in childhood but also adulthood, help us to regulate these affects, says Schore. All the play-wars, play-domesticity, play-adventures, play-science, play-everything that we see happy kids lose themselves in: these activities are building sophisticated mental equipment, to help us richly ride the torrents of later life.

(And honestly: as you sit down to your binge watch of a carefully crafted world on a streaming service, bottle of wine to hand, your beloveds as your interlocutors, who can truly claim this impulse isn’t at the heart of adult life too?)

Indeed, I have a big claim for play in adult life. We’re at the edge of various precipices, which scientific and industrial modernity has led us to. These are not just disastrous tipping points in our climate systems, which will disrupt our whole productive lives but also the possibility of a step-change in artificial intelligence, bringing new entities among us, challenging our very humanity.

As noted above, the cultural industries exploit our hopes – but mostly our fears – about how these and other trends will shock and disrupt our lives. However, I claim we urgently need to expand “grounds of play” in our lives – time and space beyond the labour market, or domestic maintenance – where we can both deliberate, and imagineer, how we negotiate these ever-more-turbulent rapids.

That’s my idiosyncratic argument for a four-day-week and a Universal Basic Income: to give us resources to be imaginative, resilient citizens, in an age of exacerbating crises.

But short of that, there’s something we can more concretely do – which is maybe easier than asking stiff, repressed adults to recover the right to prototype their lives. And that’s securing the right for children to fully and richly play, at the developmental stage they need it most.

In recent years, Scotland has been a-brim with initiatives to push back against the too-early introduction of testing to school children, and the push forward of a three-to-seven- years, relationship-and-play-centred kindergarten stage.

Led by Sue Palmer and her Upstart initiative, they have been amassing the research – often citing countries with the world’s best educational results – that could justify this reform, at least to six years, in Scottish education.

I was happy to be informed by Sue, and SNP policy convener Toni Giugliano, that a motion advocating this stage has been proposed for the SNP conference on October 8-10.

I endorse every word of it below: “The body of international evidence is in favour of play-based early years education. Active, social play is children’s natural learning drive and helps develop physical fitness, social skills, cognitive capacities and personal qualities such as creativity, problem-solving, self-regulation and emotional resilience.

“Children in European countries who attend play-based kindergarten till six or seven enjoy higher levels of health and wellbeing.

“Scotland and the UK are outliers in Europe in starting formal education at four or five, and acknowledges that since international PISA [Programme for International Student Assessment] comparisons began, countries with later school starting ages have performed better than those with earlier starts.

“On the other hand, an early start to formal education is linked to the development of social, emotional and mental health problems. There is concern at the rise in mental health problems in children in Scotland over the past decade.

‘We acknowledge the views of parents, teachers, early years experts, health professionals and campaign groups like Upstart Scotland, who believe that children under six should not face the pressures and structures of the formal school system.

“In order to succeed in closing the attainment gap, early years education must be based on relationship-centred, child-led, play-based environments with a greater focus on outdoor learning.”

And as I wrote in my quote for their pamphlet: “If you’re looking for ‘evidence-based policy’, then you’d be hard put to find something more evidenced than this … The Scottish Parliament was established to do things differently and better. This policy is in Holyrood’s best traditions – please support it fully”.

We’re in trouble. We all need to imagine our way out of this toxic niche that we are collectively trapped in.

But the least we adults can do, with the institutions we do control (as opposed to the ones we’ll have to invent), is to give our kids the best, long-term equipment for the tough future we’ve bequeathed to them.

So let the children play.