The Secret Life of Four Year Olds, Channel 4 - TV review: No one does insults like these kids

"You're just a tiny mouse on a purple toilet!" said Cuba to Skyla when she wouldn't give him a turn on the scooter

Play on: 'The Secret Life of Four-Year-Olds'

"Stop ringing me, Richard. You’re not the dad!" That's not a line of dialogue from last night’s EastEnders, that was a little girl playing makebelieve in Channel 4's hilarious and revealing fly-on-the-nursery-wall documentary The Secret Life of Four-Year-Olds. Embarrassing for her mum, perhaps, but fascinating for Dr Paul Howard-Jones and Dr Sam Wass, the two scientists observing 10 children as they met for the first time, in a classroom rigged with cameras and wired for sound.

The four-year-olds did the things that four-year-olds do – whispered secrets, threw tantrums, picked their noses – and it was surprising to note how defined their personalties already were. Big-for-his-age Chaim bulldozed his way around, snatching up toys. It was an effective way to establish dominance, but how would he fare when it came to making friends?

Skyla was a self-described cutie whose well-honed manipulation techniques work better on adults than her peers and serious, steadfast Christian was described by his parents as "a bit of an old man". Still, in his determination to finish the den-building task even after the teacher had declared the other group winners, the psychologists identified "grit", a key predictive factor in future success. Christian will be bossing us all around in approximately 40 years’ time.

Fascinating, too, was the way that one particular social skill assumed an importance above all others – sharing. Those children who knew how made friends more easily and those friends provided invaluable support when conflict arose. Speaking of conflict, no one does off-the-cuff insults quite like an excitable four-year-old: "You’re just a tiny mouse on a purple toilet!" said Cuba to Skyla when she wouldn’t give him a turn on the scooter. "You’re actually a green toilet and I’m telling my cat to scratch your face" was Skyla’s damning comeback.

We may begin learning to express emotions in nursery school, but, truth be told, many are still struggling to master this life skill long into adulthood.