Science
The science behind the sea of cubes
What pediatric experts, Montessori research and the WHO say about free, sensory play, and what we built from it.
Free play isn't a break from learning. It is learning.
When your child scoops cubes, buries treasure and digs it all up again, it looks like "just playing." Pediatric medicine sees it differently: the American Academy of Pediatrics, one of the largest pediatric associations in the world, has pulled together in two major reports what free play does to the brain. In the best possible way.
Play helps build the brain: it strengthens self-regulation, language and social skills.
Summarized from: American Academy of Pediatrics, “The Power of Play,” in the journal Pediatrics, 2018 [1]Back in 2007, the AAP stated that free play is essential to children's cognitive, physical, social and emotional development, and that it strengthens the parent-child bond along the way [2]. Researchers from the University of Cambridge and Temple University add that children learn most deeply when their play is active, self-directed and joyful [3]. Self-directed means the child decides what happens. Not the instructions, not the app, not us.
Real materials, real hands: what Montessori research shows
Maria Montessori's idea that children grasp the world through their hands is more than 100 years old, and today it is one of the most thoroughly researched approaches in early childhood education. A study in the journal Science compared children who won a place at a Montessori school in a lottery with children on the waiting list: the Montessori children did better in reading, math and social skills [4].
Children ages 3 to 6 who work with real materials every day, on their own terms, did better than their peers in academic achievement and social understanding.
Summarized from: a longitudinal study, Frontiers in Psychology, 2017 [5]In 2023, a systematic review of 32 studies found that hands-on, self-directed work with materials shows its strongest effects in the preschool years [6], exactly the age when kids get lost in a sea of cubes. Flowfull isn't certified Montessori material, but it's built on the same principles: real wood, open-ended play, and the child leads.
Small hands, big impact: fine motor skills as a foundation
Grasping, pouring, sifting, picking up a single cube between two fingers: that's precision work for little hands. And these skills turn out to matter later on: a large longitudinal analysis found that fine motor skills at school entry are among the strongest predictors of later school achievement, stronger than many classic indicators [7].
Skilled hands and good self-regulation both make a measurable contribution to achievement in kindergarten.
Summarized from: Cameron et al., Child Development, 2012 [8]An important note, because we want to stay honest: these are correlations, not guarantees. No toy in the world can promise that pouring cubes will lead to good math grades. But the direction is clear: hands that get to do lots of different things are childhood time well spent.
Why digging in feels so calming
It's the moment parents describe to us most often: a wound-up child sits down in the playpit, their hands sink into the cubes, and after a few minutes, things go quiet. Occupational therapy research has been looking at effects like this for decades, under the heading of sensory integration [9].
Deep tactile input can have a calming effect on a child's nervous system, and engaging several senses tends to work better than engaging just one.
Summarized from: a systematic review, Frontiers in Pediatrics, 2025 [10]The material plays a part, too: Japanese research shows that simply touching wood with the palm of your hand can measurably relax the body, compared with surfaces like metal or stone [11]. Reviews of research on indoor spaces point in the same direction [12]. These wood studies were done with adults. We mention them because they help explain why ten thousand wooden cubes feel different from a box of plastic balls.
And what about screen time?
No guilt trip, just numbers: the WHO recommends no more than one hour of screen time a day for 3- and 4-year-olds (the less, the better) and explicitly recommends more time for active play [13]. The American Academy of Pediatrics says the same [14]. A long-term study of around 2,400 children in JAMA Pediatrics found that the more screen time in early childhood, the weaker the children's later results in language, motor skills and social behavior [15].
Our takeaway is deliberately unspectacular: kids don't need a ban, they need an alternative with enough pull of its own. Something that fills their hands without any blinking lights. That's exactly what we built our sea of cubes for.
All sources
Every research finding on this page refers to one of these sources. The studies look at free play or sensory play, fine motor skills and material environments in general, not at this product.
- Yogman, M. et al. / AAP (2018): The Power of Play. Pediatrics 142(3). doi.org/10.1542/peds.2018-2058
- Ginsburg, K. R. / AAP (2007): The Importance of Play. Pediatrics 119(1). doi.org/10.1542/peds.2006-2697
- Zosh, J. M. et al. (2017): Learning through play - a review of the evidence. LEGO Foundation White Paper. learningthroughplay.com (PDF)
- Lillard, A. & Else-Quest, N. (2006): Evaluating Montessori Education. Science 313. doi.org/10.1126/science.1132362
- Lillard, A. S. et al. (2017): Montessori Preschool Elevates and Equalizes Child Outcomes. Frontiers in Psychology 8:1783. doi.org/10.3389/fpsyg.2017.01783
- Randolph, J. J. et al. (2023): Montessori education's impact on academic and nonacademic outcomes. Campbell Systematic Reviews 19(3). doi.org/10.1002/cl2.1330
- Grissmer, D. et al. (2010): Fine motor skills and early comprehension of the world. Developmental Psychology 46(5). doi.org/10.1037/a0020104
- Cameron, C. E. et al. (2012): Fine Motor Skills and Executive Function Both Contribute to Kindergarten Achievement. Child Development 83(4). doi.org/10.1111/j.1467-8624.2012.01768.x
- May-Benson, T. A. & Koomar, J. A. (2010): Systematic Review of Sensory Integrative Interventions. American Journal of Occupational Therapy 64(3). doi.org/10.5014/ajot.64.3.403
- Tarver, T. et al. (2025): Systematic review of sensory-based interventions for children and youth. Frontiers in Pediatrics 13. doi.org/10.3389/fped.2025.1720179
- Ikei, H., Song, C. & Miyazaki, Y. (2017): Physiological Effects of Touching Wood. IJERPH 14(7). doi.org/10.3390/ijerph14070801
- Burnard, M. D. & Kutnar, A. (2015): Wood and human stress in the built indoor environment. Wood Science and Technology 49. doi.org/10.1007/s00226-015-0747-3
- WHO (2019): Guidelines on physical activity, sedentary behaviour and sleep for children under 5. who.int/publications
- AAP Council on Communications and Media (2016): Media and Young Minds. Pediatrics 138(5). doi.org/10.1542/peds.2016-2591
- Madigan, S. et al. (2019): Association Between Screen Time and Children's Performance on a Developmental Screening Test. JAMA Pediatrics 173(3). doi.org/10.1001/jamapediatrics.2018.5056
From research to a sea of cubes
A soft playpit, thousands of wooden cubes, open-ended play for ages 3+, and a 100-day trial right in your own living room.
Discover the Sensory Playpit More from the Magazine →Note: The studies cited look at free play or sensory play, fine motor skills and material environments in general, not at this product. Flowfull is not a therapy or medical product, and it is not certified Montessori material.
