Screen time under five, in plain language

Screen time advice for small children is quoted constantly and read rarely. Two organisations set most of it, they do not agree in emphasis, and the disagreement tells you more than either set of numbers does on its own.

We are not a health authority and nothing here is our advice. What follows is what these two bodies actually published, with the reasoning they gave.

What the World Health Organization says

In 2019 the WHO issued guidelines on physical activity, sedentary behaviour and sleep for children under five. The screen element is short and specific:

• Under 1 year: no screen time.
• 1 to 2 years: no sedentary screen time at 1. At 2, if any, no more than one hour — and less is better.
• 3 to 4 years: no more than one hour of sedentary screen time, and less is better.

The framing matters. These guidelines are not primarily about screens. They are about how the twenty-four hours of a young child's day are spent, and the screen limits sit next to targets for physical activity and for sleep. The concern is what sitting still in front of a screen displaces.

What the American Academy of Pediatrics says

The AAP's long-standing recommendations are close but not identical:

• Under 18 months: avoid screens other than video chat.
• 18 to 24 months: if you introduce digital media, watch it with your child rather than leaving them to it alone.
• 2 to 5 years: around an hour a day of high-quality programming, watched together where possible.

The video-chat exception is deliberate. A call with a grandparent is a conversation with a responsive person, which is a different thing from watching a video, and the evidence has treated it differently.

More recently the AAP has moved away from the clock as the main tool, promoting a framework built around what the child is like, what the content is, whether use is calm or dysregulating, what it is crowding out, and whether it is being talked about. The shift is an admission that an hour of a grandparent on video and an hour of autoplaying clips at bedtime are not the same hour.

Where they differ, and why that is the interesting part

The WHO gives you a number. The AAP increasingly gives you a set of questions.

Both are responding to the same limitation: the research is much stronger on what heavy screen use displaces — sleep, physical activity, and above all back-and-forth talk with an adult — than it is on screens as a direct cause of harm at low levels. Displacement is measurable. Direct effect at moderate levels is contested.

Read that way, the two positions stop conflicting. The number is a proxy for the displacement, and the questions are an attempt to measure the displacement directly.

Background television is the overlooked one

Most of the argument is about what a child watches. A consistent finding in the research is that a television playing in the room while a child does something else is also costly, even when nobody is watching it.

The mechanism is the one already described. Background media reduces the amount and the quality of talk between adult and child, and it fragments play — children in rooms with a television on switch activity more often and stay with each thing for less time. None of that time appears in anyone's count of screen time, because nobody was watching.

"High quality" is doing a lot of work

The AAP's phrase for what is acceptable at two to five is high-quality programming, which sounds like a content rating and is closer to a design one. The features that recur are slow pacing, a clear narrative, real-world subject matter, and moments that invite a response rather than filling every second.

The counter-example is autoplay. A queue that never ends removes the only natural stopping point a child had, and it is the single setting most worth turning off.

There is also a well-documented effect sometimes called the video deficit: under about two and a half, children learn a task markedly better from a person in the room than from a recording of the same person doing the same thing. That is not an argument that video is harmful. It is an argument that it is a poor substitute for the adult, which is what the guidance keeps saying.

What this looks like in a real week

A few things follow from the reasoning rather than from the numbers.

Ask what the screen replaced, not what it cost. Twenty minutes that replaced staring out of a window is not the same as twenty minutes that replaced the only outdoor time available that day.

Talking is the ingredient. The most consistent finding across early childhood research is the value of responsive back-and-forth conversation. That is why co-viewing keeps appearing in the guidance — a narrated video is partly a conversation.

Evenings are the expensive slot. The sleep evidence is the firmest part of the picture, and screens close to bedtime are where a small amount of use costs the most.

The parent's screen counts too. A phone in an adult's hand during a meal or a nappy change interrupts exactly the exchange the guidance is trying to protect. This is the part of the advice that gets quoted least often.

What nobody can tell you

Neither body claims a threshold at which harm begins. There is no evidence for a cliff edge, and the honest position is that the numbers are pragmatic defaults rather than measured limits.

Which is why the guidance is worth reading in full rather than in headline form. Both organisations publish theirs openly, and if you are making a decision about your own child, they are a better source than anyone selling you something.