The Science of Play

You feel the pull to make every hour count. Another worksheet, another read-aloud, another enrichment class — and underneath it, a low hum of guilt when your child is just... playing. For a lot of us, play is the thing we allow after the real learning is done. It's the dessert, not the vegetables.

The research asks you to flip that picture. For one of the most important sets of cognitive skills your child will ever develop, unstructured play isn't the reward for learning. It is the learning. And that means you can stop feeling guilty about protecting it.

The thesis of this issue is straightforward, with one honest caveat built in: free, child-directed play is one of the primary ways children build executive function — the mental control system behind self-regulation, focus, and problem-solving. The caveat is that the evidence, while real and pointing consistently in one direction, is modest in size and depends heavily on the play being genuinely child-directed. This issue is about what the science actually supports, and how to act on it without overclaiming.

Let's start with authority, because this is a topic where parents get a lot of conflicting noise. In 2018, the American Academy of Pediatrics published a clinical report titled The Power of Play, reaffirmed as recently as January 2025. Its position is unambiguous: developmentally appropriate play "promotes the social-emotional, cognitive, language, and self-regulation skills that build executive function." The report goes further, stating plainly that "play is not frivolous" — it "enhances brain structure and function and promotes executive function (ie, the process of learning, rather than the content)" (Yogman et al., 2018). When the flagship pediatrics body in the country says play builds the brain's control system, that's a strong place to begin.

So what is executive function, exactly? It's the set of mental processes that let a person regulate their own thought and behavior — holding a goal in mind, ignoring distractions, stopping an impulse, and switching approaches when something isn't working. Researchers usually break it into three core parts: inhibitory control (stopping yourself), working memory (holding and using information), and cognitive flexibility (shifting and adapting). These skills predict school readiness, academic performance, and even health and financial outcomes decades later.

The single most important study for our purposes comes from Barker and colleagues at the University of Colorado Boulder. In a 2014 study — reviewed, notably, by two of the biggest names in the field, Adele Diamond and Angeline Lillard — the researchers tracked how 6- and 7-year-olds spent their time and then measured their executive function. The finding was striking: the more time children spent in less-structured activities, the better their self-directed executive functioning. The opposite held for structured, adult-led time, which predicted worse self-directed executive function (Barker et al., 2014).

That word "self-directed" is the whole ballgame, so it's worth slowing down. There are two kinds of executive function. Externally-driven EF is when a child does the right thing because an adult tells them what to do and when — "now put on your coat," "now switch to sorting by color." Self-directed EF is when the child figures out on their own what the goal is and when to act — putting on the coat because they decided it's cold. Self-directed EF is harder, develops later, and matters more for real-world independence. Barker's work suggests that unstructured time is where children get to practice it, because no adult is there setting the goal for them.

Now for the honest part. In 2026, Constien and colleagues published a pre-registered meta-analysis in Developmental Review pooling 26 studies of nearly 3,000 young children. They found a statistically significant relationship between pretend play and executive function — but a small one, with a correlation of r = 0.17, and no evidence of publication bias (Constien et al., 2026). I'm telling you the effect is small on purpose. You are the kind of reader who would rather have the real number than a hyped one, and a small-but-real effect is still worth acting on — especially for an activity that costs nothing and children want to do anyway.

There's also promising real-world evidence. A 2022 study by Koepp and colleagues took 72 preschoolers and compared their behavior after indoor versus outdoor free play. Children showed noticeably better attention during classroom circle time after outdoor free play than after indoor play (Koepp et al., 2022). Worth noting honestly: this benefit showed up in real classroom observation, not in the lab-based cognitive tasks — a reminder that where and how you measure matters, and that the everyday, observable payoff may be the one that counts most for a homeschool day.

Finally, a necessary counterweight. Adele Diamond — arguably the most cited authority on executive function alive — co-authored a widely referenced 2016 review specifically warning against overhyping any single intervention for improving EF. Her central conclusion is one worth taping to the wall: executive functions are best supported not by drilling them in isolation, but when a child's emotional, social, and physical needs are also met (Diamond & Ling, 2016). Rich, child-directed play — which is social, physical, emotionally engaging, and joyful all at once — happens to check every one of those boxes. Play isn't magic. It's just unusually good at meeting the conditions under which executive function grows.

Three terms make the strategy clear. Executive function is the brain's self-management system — inhibitory control, working memory, and cognitive flexibility. Self-directed executive function is the harder, more valuable version, where the child decides what to do and when, rather than following an adult's cues. And unstructured (child-directed) play is play with no adult-set goal and no script — the child invents the point of it.

Here's the reframe that matters most: the goal is not "less structure" as some kind of virtue. The goal is to protect a meaningful block of genuinely child-directed time alongside your academics. Structure and freedom are not enemies; a homeschool day needs both. The mistake is letting structure quietly eat all the free time.

In practice, that comes down to three habits. First, protect a daily unstructured block. Guard a real, uninterrupted stretch of open, child-led time — not five minutes between subjects, but a genuine window where there is no assigned goal and no adult script. Second, step back instead of directing. This is the counterintuitive one. During free play, resist the urge to narrate, correct, or steer toward something "educational." The cognitive work — the executive-function practice — is happening precisely because the child is setting and monitoring their own goals. The moment you take over the goal-setting, you've quietly converted self-directed practice back into following instructions. Third, offer open-ended materials. Blocks, loose parts, art supplies, dress-up bins, a yard — things that invite the child to invent the goal, rather than "educational" toys that tell the child exactly what to do.

The trap to name is the Over-Scheduling Trap. It's the achievement-minded parent's default failure mode: filling every hour with adult-led lessons, classes, and enrichment in the sincere belief that more structure equals more learning. The research says otherwise for this particular skill set. Barker's finding was that more structured time predicted worse self-directed executive function. When you replace all the open time with adult-directed activity, you don't add executive-function practice — you remove the conditions under which the hardest, most valuable form of it develops. A packed schedule can look like rigor and quietly function as the opposite.

A few research-aligned, low-cost places to start:

Open-ended materials over "educational" toys. Blocks, loose parts, art supplies, and dress-up bins force the child to generate the goal themselves — which is the exact mechanism the research points to. A toy that does one scripted thing does the executive work for the child. Outdoor and nature time. A yard, a park, or any regular outdoor free-play space; Koepp and colleagues link outdoor free play to better subsequent classroom attention, and it comes with movement and sensory richness for free. And finally, the AAP "Power of Play" report, which is free to read online — because you're the kind of reader who wants the primary source, not someone else's summary of it.

Here's my question for you this week: How much genuinely unstructured, child-directed time does your homeschool day include right now — and does protecting it feel easy or hard for you? Reply and tell me. I read every response, and I suspect "hard" is the honest answer for a lot of us.

[1] Yogman, M., Garner, A., Hutchinson, J., Hirsh-Pasek, K., Golinkoff, R. M., et al. (2018). The Power of Play: A Pediatric Role in Enhancing Development in Young Children. Pediatrics, 142(3), e20182058. https://publications.aap.org/pediatrics/article/142/3/e20182058/38649/The-Power-of-Play-A-Pediatric-Role-in-Enhancing

[2] Barker, J. E., Semenov, A. D., Michaelson, L., Provan, L. S., Snyder, H. R., & Munakata, Y. (2014). Less-structured time in children's daily lives predicts self-directed executive functioning. Frontiers in Psychology, 5, 593. https://www.frontiersin.org/journals/psychology/articles/10.3389/fpsyg.2014.00593/full

[3] Constien, T., Moran, S., Rooney, B., & Downes, M. (2026). A head taller: A meta-analysis on the relation between pretend play and executive functions in early childhood. Developmental Review, 79, 101249. https://www.sciencedirect.com/science/article/pii/S0273229726000055

[4] Koepp, A. E., Gershoff, E. T., Castelli, D. M., & Bryan, A. E. (2022). Preschoolers' executive functions following indoor and outdoor free play. Trends in Neuroscience and Education, 28, 100182. https://www.sciencedirect.com/science/article/pii/S2211949322000114

[5] Diamond, A., & Ling, D. S. (2016). Conclusions about interventions, programs, and approaches for improving executive functions that appear justified and those that, despite much hype, do not. Developmental Cognitive Neuroscience, 18, 34–48. https://www.sciencedirect.com/science/article/pii/S1878929315300517