Parenting

Why Babies Love Peekaboo at a Certain Age: The Brain Science

Rive News Research Desk

Published October 13, 2026 · 7 min read

Key takeaways

Babies love peekaboo because it blends surprise with prediction: they learn to expect the reveal, and the payoff delights them every time.
The game peaks between 6 and 12 months, exactly when object permanence is forming and the baby's predictions get strong enough to enjoy.
Research shows peekaboo also builds trust, turn-taking, and emotional regulation, making it far more than a silly game.

A laughing baby mid-giggle — A baby laughing during play. The giggles peekaboo produces are tied to a real cognitive workoutPhotograph: Wikimedia CommonsImage: Wikimedia Commons

Every culture has its own version of peekaboo. A caregiver covers their face, pauses, and reveals it with a flourish.

The baby shrieks with laughter. Then everyone does it again, and again, and again.

The game's universality is a clue that it taps something fundamental in the developing mind.

Babies love peekaboo most intensely at a certain age, roughly from 6 to 12 months, and the timing is no accident. That window is when the brain is working out some of its biggest ideas about how reality works.

Peekaboo is the lab where the experiments happen.

This article explains why babies love peekaboo, what the game teaches their brains, and why the laughter follows such a predictable schedule.

Peekaboo is a physics lesson in disguise

The Swiss psychologist Jean Piaget called the core principle object permanence: the understanding that things keep existing when out of sight. He argued babies spend the first two years working it out, and those two years are prime peekaboo time.

Looked at this way, the game is not just a joke. It lets babies test and re-test a fundamental principle of existence.

You disappear. You still exist. You come back.

Every round delivers the same lesson, and the repetition is the point. Developmental psychologist Aliza Pressman has described the rhythm as "I'm gone... I'm back," a loop that teaches the infant the world is predictable.

Before about 6 months, the game works differently. A very young baby may simply enjoy the looming face and the voice, without grasping the disappearance at all.

By 8 or 9 months, babies actively search for hidden things, and peekaboo becomes a confirmation of something they are figuring out. By 9 to 12 months, many can play the hiding role themselves, which is why the game evolves rather than getting boring.

The surprise formula, tested in a lab

Peekaboo uses the basic structure of a good joke: surprise balanced with expectation. Researchers Gerrod Parrott and Henry Gleitman tested this directly with groups of six, seven, and eight-month-olds, in an experiment that sounds like more fun than a psychology study should be.

Most of the time, the peekaboo game proceeded normally. But on occasional trick trials, the adult hid and reappeared as a different adult, or reappeared in a different location.

Independent observers rated videos of the infants for smiling and laughter.

The babies smiled and laughed less on the trick trials, even though those outcomes were more surprising. And the gap between enjoyment of normal and trick peekaboo grew with age: the eight-month-olds liked the trick trials least.

The researchers' interpretation was that the game depends on predicting the outcome. As babies get older, their prediction gets stronger, so a violated prediction is less funny, not more.

That finding explains the age curve beautifully. Peekaboo is funniest when the baby knows enough to predict the reveal but is still delighted to be right.

Too young, and there is no prediction. Too old, and the prediction is so certain the game needs new variations to stay interesting.

More than a joke: what else the game builds

Laughter is the headline, but developmental psychologists credit peekaboo with a stack of quieter benefits. Caspar Addyman, a developmental psychologist and former director of the Goldsmiths InfantLab who studies what makes babies laugh, puts it simply: "Babies who laugh more, learn more."

The social benefits start with bonding. Peekaboo creates face-to-face interaction where the baby has the caregiver's full attention as an equal partner.

Addyman notes that versions of the game exist in cultures all over the world, and that the shared attention delights babies because it teaches them about the social world.

The game also rehearses separation on a tiny, safe scale. The face goes away and returns, which lets babies experience brief absence with a guaranteed happy ending.

That gentle rehearsal helps them cope with real separations, the ones that trigger separation anxiety as object permanence develops.

Then there is turn-taking. Peekaboo has a built-in rhythm of action and response, and babies learn to anticipate their turn to reveal or react.

That back-and-forth is a foundation for conversation: eye contact, timing, and reading another person's cues. The emotional payoff matters too.

The surprise elicits joy, and shared laughter strengthens the attachment between baby and caregiver.

A 19th century painting of an adult playing with a baby. Grown-ups have been rediscovering this game with every generationPhotograph: Wikimedia CommonsImage: Wikimedia Commons

Why the game never really gets old

One secret of peekaboo's durability is that it is not a single game. As the baby grows, caregivers instinctively adapt it to new abilities.

The earliest version is simple looming: the adult announces themselves with their voice before bringing their face into focus. Later comes classic hiding and reappearing.

After a year or so, the baby takes control and does the hiding.

Each version keeps the same balance that made the original work: what the baby knows, what the baby can control, and what still surprises them. That is why adults enjoy the repetition as much as babies do.

The laughter is genuinely contagious, and the game keeps paying out in connection long after the cognitive lesson is learned.

There is also a trust dividend. Every successful round is a small promise kept.

You said you would come back, and you did. Repeated hundreds of times, that pattern becomes one of the baby's first working models of reliability in other people.

A baby photographed in natural light — A baby during playtime. Around 6 to 12 months, games of disappearance and return are at their most thrillingPhotograph: Wikimedia CommonsImage: Wikimedia Commons

Common questions about peekaboo

At what age do babies start enjoying peekaboo?

Most babies start responding around 4 to 6 months and love it most between 6 and 12 months. By 9 to 12 months, many initiate the game themselves by hiding their own faces or ducking behind furniture.

Is peekaboo actually good for development?

Yes. It exercises object permanence, builds trust through predictable returns, rehearses turn-taking, and gives babies safe practice with brief separation.

Researchers describe it as a cognitive and social workout disguised as a game.

What if my baby does not like peekaboo?

Temperament varies. Some babies find the surprise overstimulating rather than funny.

Try gentler versions with slower reveals, or switch to hiding toys instead of faces. Lack of interest is not a developmental red flag on its own.

When do babies outgrow peekaboo?

They rarely outgrow it so much as graduate. Toddlers convert it into hide-and-seek and elaborate hiding games, which exercise the same mental machinery at a higher difficulty level.

The bottom line

Babies love peekaboo at a certain age because their brains are ready for exactly what the game offers: a surprise they can predict. The 6 to 12 month window lines up with the formation of object permanence, and the Parrott and Gleitman experiments show the laughter depends on expectation, not just novelty.

Underneath the giggles, the game is building trust, timing, and the concept that people who disappear still exist. That is a lot of work for a game with no equipment.

Tags: peekaboo, baby development, object permanence, play

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