"Young children's brains don't learn best from a lot of stimulation. They learn best from doing the same thing over and over again, in a slow-paced, predictable, repetitious way." -
Professor Sam Wass, Professor of Developmental Cognitive Neuroscience, University of East London
The food hasn't come yet. Everyone's a bit hungry. Your toddler is starting to slide off the chair. You reach for the phone, pull up Peppa Pig, and the table goes quiet.
Most parents know this moment. Professor Sam Wass knows it too; he has three children under six, and he's the first to say the urge is real. He's also Professor of Developmental Cognitive Neuroscience at the University of East London, head of the Baby Dev Lab, and one of the psychologists from Channel 4's The Secret Life of 4 and 5 Year Olds. He's spent his career studying how young brains develop attention, how stress responses form, and what the modern environment is doing to a developing nervous system. On this episode of Best Beginnings, he sat down with us to talk about what the neuroscience actually says and what it means for parents.
The illusion of calm
The first thing worth knowing is what's actually happening in a child's body when they're watching fast-paced content. From the outside, they look completely still. The constant motion stops. Their face goes blank. It looks like calm.
It isn't.
Sam's lab measures children's heart rates and stress responses while they watch screens, and what they find is the opposite of what the stillness suggests. The heart is going fast. Energy is flooding the muscles. The child's nervous system has gone into fight or flight mode, the same survival response designed for genuine threat.
Why? Because young brains are prediction machines, and they work much more slowly than ours. An eighteen-month-old can process about one frame change per second. An adult can process ten. Modern children's content moves far faster than that, with more cuts, more overlapping speech, more plot points per minute. When the world is coming at a child faster than they can predict it, a hardwired evolutionary mechanism kicks in: I can't anticipate what's about to happen, so I'd better be ready to respond at any moment. The body floods with energy it has nowhere to put.
This is why, as Sam puts it, every parent will recognise that children come off screens ratty. The mood crash isn't really about the transition. It's a stress response discharging.
His lab is now investigating whether spending sustained periods in this high-arousal state during the years when stress response systems are still forming might contribute to the rising rates of anxiety and depression we're seeing later in life. The evidence is early, but the mechanism makes sense.
To make the speed difference concrete, Sam describes an experiment he's done with his own kids (his wife, he admits, thinks it's a bit weird). He holds a ball up where the baby can see it, then drops it from one hand into the other. The baby's face goes: Oh. Where did that go? Oh, there it is, in Daddy's hand. They genuinely can't see it move. Anything faster than a second is invisible to them.
Now think about what's on screen.
The myth of stimulation
If there's one thing Sam wants parents to stop believing, it's that more stimulation means more learning.
He describes picking up his daughter from nursery and getting the daily handover: today we did this, and this, and this, and this. He never said it out loud (he's pretty sure they'd have thought he'd lost it) but what he wanted to say was: what you should be telling me is that today she did exactly the same things, at exactly the same times, as she did yesterday. And the day before.
Young children's brains, he explains, are a "big, jumbled, over-connected mess." Synapses peak somewhere between two and five. What that mess needs in order to organise itself isn't novelty and enrichment and a busy schedule. It's repetition. Predictability. The same thing, in the same order, at the same time, day after day.
This is why a twelve-month-old who accidentally knocks a spoon off the highchair and watches you pick it up will, with absolute certainty, immediately knock it off again. They're not winding you up. They're checking the prediction. They crave predictable interactions because predictability is how their brains learn.
It's why young children in nurseries gravitate to adults before other children; adults are more predictable. It's why the school-holiday meltdown is real: the rhythms the child's body had learned to rely on have been pulled out, and there's nothing for the day to organise itself around.
The implication is uncomfortable, because it cuts against most of what parents are told. The instinct to enrich, to expose, to fill the day with stimulation; that's an adult reading of what a young brain needs. The brain itself wants the spoon to fall off the table, again, at the same time, every morning.
The tantrum trap
Handing over a screen during a meltdown works. Visibly, instantly, reliably. The tension goes out of the child's face within seconds, and a parent who was about to lose their grip on the morning gets to breathe.
But research from colleagues of Sam's in the US, Heather Kirkorian, Rachel Barr and others, found something parents really should know. The bad mood doesn't go anywhere. It's there for the duration of the screen, just held off the face. The moment the screen comes off, it returns. And, more troublingly, across multiple studies they found that the more screens are used to manage toddler tantrums, the worse the behavioural dysregulation gets over time. The calm is real for the child holding the iPad. But something is happening underneath: a difficult feeling is being suppressed rather than processed, and a young brain that should be learning how to ride out hard emotions is being taught, repeatedly, that the way through is a screen.
When parents need a break, and they will, Sam is gentle about it. The most reliable reset he knows of is, in his phrase, "screen time to green time." The fastest way to bring a child out of fight or flight is to throw open the back door and let them run. Movement, daylight, space.
The phone in your hand
There's a finding in developmental psychology called the still-face protocol. It's one of the most replicated experiments in the field. A parent and child sit across from each other and interact normally. At a signal, the parent's face goes blank and unresponsive. Within seconds, the child becomes distressed. Researchers measure the stress response.
Sam's lab used to run still-face studies. They can't anymore, because the situation it was designed to test, a parent suddenly going non-responsive, is no longer a brief experimental stressor. It's a regular feature of childhood.
A child can't see what's on your phone. They're at floor level. From their point of view, you've just vanished. The parent who was there a moment ago is staring, frozen, at a small object that has somehow taken precedence over them. And it happens at the dinner table, in the car, in the playground, throughout the day, during the years when their sense of safety is being built. This is one of those things that doesn't need a study to feel true once it's been pointed out. But the studies are there.
Five minutes on the floor
After all this, what Sam offers as the single most effective thing a parent can do for their child's brain development is almost embarrassingly simple. It doesn't require a curriculum, a class, or a programme. It takes about five minutes.
Get down on the floor. See the world from your child's height. Be there.
He describes doing it with his four-year-old before the day starts, before the meetings creep in. With his five-month-old he describes something more demanding, forcing his fast adult brain to slow to her pace, holding her gaze, being properly still. He calls it a two-minute meditation. He says it does as much for him as it does for her.
The neuroscience of why this matters has to do with shared engagement and physiological synchrony. When a parent and child are genuinely co-present, their heart rates and stress responses begin to mirror each other. The parent's brain tracks the child's in remarkable detail, anticipating the moments their attention is about to drift, pulling them back with a word, a movement, a smile, feeding new information in at exactly the moment the brain is ready to receive it. No screen can do this. A screen plays its content on a fixed timeline whether the child is paying attention or not. A parent on the floor is the most sophisticated learning environment a young brain will ever encounter.
Sam talks about walking his son up and down four flights of stairs in the family's old narrow house when he wouldn't settle as a baby. By the bottom of the stairs his own heart was going. By the top, the baby's heart had matched his, then both came down together. That, in physiological terms, is co-regulation. It's also just a dad pacing the stairs with a fractious baby.
They're the same thing.
What this isn't
It would be easy to read all of this as another set of demands on parents who already feel they aren't doing enough. That isn't what Sam is saying.
He's not telling parents to do more. He's saying that quite a lot of what we've been told to do, the enrichment, the stimulation, the educational content, the reaching for a screen to smooth over the hard moments, is, in neuroscience terms, the wrong direction. The thing young brains need most is the thing modern life keeps pulling away: a slow pace, a familiar rhythm, a parent who is properly there for a few minutes a day.
In Sam's own house there are screens. There are tantrums. The 44 minutes of screen time per day is negotiated in advance; his kids work out how many episodes that buys them, and there are mornings he loses his patience and tells his children they can't be upset right now because it's inconvenient for him. He's not above any of this. None of us are.
What he's offering is a quieter argument: that the small, ordinary, repetitive moments, the spoon falling off the table for the fifteenth time, the five minutes on the floor before the day begins, the walk up the stairs with a baby who won't settle, aren't filler around the important parenting. They are the important parenting. They're the architecture going in.
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