Science supports many of our intuitions about the benefits of play.
Playful behavior appears to have positive effects on the brain and on a child’s ability to learn. In fact, play may function as an important, if not crucial, mode for learning.
Want specifics? Here are some examples.
Animal experiments: Play improves memory and stimulates the growth of the cerebral cortex
In 1964, Marion Diamond and her colleagues published an exciting paper about brain growth in rats. The neuroscientists had conducted a landmark experiment, raising some rats in boring, solitary confinement and others in exciting, toy-filled colonies.
When researchers examined the rats’ brains, they discovered that the “enriched” rats had thicker cerebral cortices than did the “impoverished” rats (Diamond et al 1964).
Subsequent research confirmed the results—rats raised stimulating environments had bigger brains.
They were smarter, too--able to find their way through mazes more quickly (Greenough and Black 1992).
Do these benefits of play extend to humans? Ethical considerations prevent us from performing similar experiments on kids. But it seems likely that human brains respond to play and exploration in similar ways.
Play and exploration trigger the secretion of BDNF, a substance essential for the growth of brain cells
Again, no one has figured out an ethical way to test this on humans, so the evidence comes from rats: After bouts of rough-and-tumble play, rats show increased levels of brain-derived neurotrophic factor (BDNF) in their brains (Gordon et al 2003). BDNF is essential for the growth and maintenance of brain cells. BDNF levels are also increased after rats are allowed to explore (Huber et al 2007).
Kids pay more attention to academic tasks when they are given frequent, brief opportunities for free play
Several experimental studies show that school kids pay more attention to academics after they’ve had a recess--an unstructured break in which kids are free to play without direction from adults (see Pellegrini and Holmes 2006 for a review).
There is some circumstantial evidence, too: Chinese and Japanese students, who are among the best achievers in the world, attend schools that provide short breaks every 50 minutes (Stevenson and Lee 1990).
Note that physical education classes are not effective substitutes for free playtime (Bjorkland and Pellegrini 2000).
Physical exercise has important cognitive benefits in its own right. But physical education classes don't deliver the same benefits as recess. Researchers suspect that's because PE classes are too structured and rely too much on adult-imposed rules. To reap all the benefits of play, a play break must be truly playful.
How long should recess be? No one knows for sure, but there is some evidence for recesses between 10 and 30 minutes. In a small study of 4-5 year olds, researchers found that recesses of 10 or 20 minutes enhanced classroom attention. Recesses as long as 30 minutes had the opposite effect (Pelligrini and Holmes 2006).
Language and the benefits of play
Studies reveal a link between play--particularly symbolic, pretend play--and the development of language skills. For example:
Psychologist Edward Fisher analyzed 46 published studies of the cognitive benefits of play (Fisher 1999). He found that “sociodramatic play”—what happens when kids pretend together—“results in improved performances in both cognitive-linguistic and social affective domains.”
A study of British children, aged 1-6 years, measured kids’ capacity for symbolic play (Lewis et al 2000). Kids were asked to perform such symbolic tasks as substituting a teddy bear for an absent object. Researchers found that kids who scored higher on a test of symbolic play had better language skills—both receptive language (what a child understands) and expressive language (the words she speaks). These results remained significant even after controlling for the age of the child.
Recent research also suggests that playing with blocks contributes to language development. For more information, see this article about construction toys and the benefits of play.
Evidence that play promotes creative problem solving
Psychologists distinguish two types of problem--convergent and divergent. A convergent problem has a single correct solution or answer. A divergent problem yields itself to multiple solutions.
Some research suggests that the way kids play contributes to their ability to solve divergent problems.
For instance, in one experiment, researchers presented preschoolers with two types of play materials (Pepler and Ross 1981). Some kids were given materials for convergent play (i.e., puzzle pieces). Other kids were given materials for divergent play (blocks). Kids were given time to play and then were tested on their ability to solve problems.
The results? Kids given divergent play materials performed better on divergent problems. They also showed more creativity in their attempts to solve the problems (Pepler and Ross 1981).
Another experimental study hints at a causal connection between pretend play (discussed at more length below) and divergent problem-solving ability (Wyver and Spence 1999). Kids given training in pretend play showed an increased ability to solve divergent problems, and the converse was true as well: Kids trained to solve divergent problems showed increased rates of pretend play.
Make-believe, self-regulation, and reasoning about possible worlds
Divergent problem solving isn't the only cognitive skill linked with make-believe. Pretend play has also been correlated with two crucial skill sets--the ability to self-regulate (impulses, emotions, attention) and the ability to reason counterfactually.
In the first case, studies report that kids who engage in frequent, pretend play have stronger self-regulation skills. Although more research is needed to determine if the link is causal (Lillard et al 2013), the data are consistent with this possibility, and the idea has intuitive appeal. You can't pretend with another person unless both of you agree about what you are pretending. So players must conform to a set of rules, and practice conforming to such rules might help kids develop better self-control over time.
In the second case, many researchers have noted similarities between pretend play and counterfactual reasoning, the ability to make inferences about events that have not actually occurred.
Alison Gopnik and her colleagues (Walker and Gopnik 2013; Buchsbaum et al 2012) argue that
counterfactual reasoning helps us plan and learn by permitting us to think through "what if" scenarios. Pretend play taps into the same skill set. So perhaps pretend play provides children with valuable opportunities to improve their reasoning about possible worlds.
In support of this idea, researchers found evidence of a link between counterfactual reasoning and pretend play in preschoolers, and this correlation remained statistically significant even after controlling for a child's ability to suppress her impulses (Buchsbaum et al 2012).
Math skills and the benefits of play
Here's an intriguing story about play and mathematics:
A longitudinal study measured the complexity of children’s block play at age 4 and then tracked their academic performance through high school (Wolfgang, Stannard, & Jones, 2001).
Researchers found that the complexity of block play predicted kids’ mathematics achievements in high school. In particular, those who had used blocks in more sophisticated ways as preschoolers had better math grades and took more math courses (including honors’ courses) as teenagers.
Of course, these results might merely tell us that kids who are smart in preschool continue to be smart in high school.
But it’s not that simple. The association between block play and math performance remained even after researchers controlled for a child’s IQ. It therefore seems plausible that block play itself influenced the cognitive development of these kids.
Playful experiences are learning experiences
Finally, lest anybody doubt that kids learn through play, we should keep in mind the following points.
1. Most play involves exploration, and exploration is, by definition, an act of investigation.
It's easy to see how this applies to a budding scientist who is playing with magnets, but it also applies to far less intellectual pursuits, like the rough-and-tumble play in puppies. The animals are testing social bonds and learning how to control their impulses, so that friendly wrestling doesn't turn into anti-social aggression. Play is learning.
2. Play is self-motivated and fun.
Thus, anything learned during play is knowledge gained without the perception of hard work. This is in contrast with activities that we perform as duties. When learning is perceived to be arduous, our ability to stay focused may feel like a limited resource that is drained over time (Inzlicht et al 2014). And it's hard to achieve a state of flow, the psychological experience of being totally, and happily, immersed in what you are doing. Play is an obvious gateway to the state of flow.
3. These arguments aside, there is also empirical evidence that kids treat play as a tutorial for coping with real life challenges.
All around the world, children engage in pretend play that simulates the sorts of activities they will need to master as adults (Lancy 2008), suggesting such play is a form of practice. And when kids are fed information during pretend play--from more knowledgeable peers or adults--they take it in. Experiments on American preschoolers suggest that children as young as 3 understand make distinctions between realistic and fanciful pretending, and use information learned from realistic pretend scenarios to understand the real world (Sutherland and Friedman 2012; 2013).
The takeaway? Giving children play-breaks and making children's academic lessons more playful isn't mere sugar-coating. It might be a way to enhance kids' natural capacities for intense, self-motivated learning.
More information on the benefits of play
Why should we encourage pretend play? Discusses the evidence regarding self-regulation and counterfactual reasoning.
In "Harry Potter makes you smarter: How magic unleashes kids’ creative thought," I discuss an experiment suggesting that fantasy makes children more inventive.
"When 'daycare' was run by kids" talks about the most common pattern of child's play in human history--the mixed age playgroup.
"Should kids be grouped by age?" considers how young children may benefit from these mixed age playgroups.
In "Lack of free play harms kids," I talk about the speculations of psychologist Peter Gray about the benefits of play.
For a popular defense of the benefits of play, check out the book
by developmental psychologists Kathy Hirsch-Pasek, Roberta Michnick Golinkoff and Diane Eyer (Rodale 2003). It's a good resource for parents who want to resist the pressure to "over-program" their children's lives. The authors make a strong theoretical case for the cognitive benefits of play, and offer many research-based suggestions for making playtime more stimulating and educational.
And here are the scientific studies cited in this article:
Bjorkland DF and Pellegrini AD. 2000. Child development and evolutionary psychology. Child Development 71: 1687-1708.
Buchsbaum D, Bridgers S, Skolnick Weisberg D, Gopnik A. 2012. The power of possibility: causal learning, counterfactual reasoning, and pretend play. Philos Trans R Soc Lond B Biol Sci. 367(1599):2202-12.
Carlson SM, White RE, Davis-Unger A. 2014. Evidence for a relation between executive function and pretense representation in preschool children. Cogn Dev. 29: 1-16.
Dickinson, D.K., & Tabors, P.O. (Eds.) (2001). Beginning literacy with language: Young children learning at home and school. Baltimore: Paul Brookes Publishing.
Fisher, Edward P. (1992). The impact of play on development: A meta-analysis. Play and Culture, 5(2), 159-181.
Gordon NS, Burke S, Akil H, Watson SJ, and Panskepp J. 2003. Socially-induced brain ‘fertilization’: play promotes brain derived neurotrophic factor transcription in the amygdala and dorsolateral frontal cortex in juvenile rats. Neuroscience Letters 341(1): 17-20.
Gosso Y., Otta E., Morais M. L. S., Ribeiro F. J. L., Bussab V. S. R. 2005. Play in hunter-gatherer society. In The nature of play: great apes and humans (eds Pellegrini A. D., Smith P. K., editors. ), pp. 213–253 New York, NY: Guilford.
Greenough WT and Black JE. Induction of brain structure by experience: substrates for cognitive development. In: Gunnar MR, Nelson CA, eds. Minnesota Symposia on Child Psychology: Developmental Neuroscience. Vol 24. Hillside, NJ: Lawrence A Erlbaum Associates; 1992:155-200.
Huber R, Tonini G, and Cirelli C. 2007. Exploratory behavior, cortical BDNF expression, and sleep homeostasis. Sleep 30(2):129-39.
Inzlicht M, Schmeichel BJ, and Macrae CN. 2014. Why self-control seems (but may not be) limited. Trends in Cognitive Sciences http://dx.doi.org/10.1016/j.tics.2013.12.009
Lewis P, Boucher J, Lupton L and Watson S. 2000. Relationships between symbolic play, functional play, verbal and non-verbal ability in young children. Int J Lang Commun Disord. 35(1):117-27.
Pelligrini AD and Holmes RM. 2006. The role of recess in primary school. In D.Singer, R. Golinkoff, & K. Hirsh-Pasek (Eds.), Play=learning: How play motivates and enhances children’s cognitive and socio-emotional growth. New York: Oxford University Press.
Pepler DJ and Ross HS. 1981. The effects of play on convergent and divergent problem solving. Child Development 52(4): 1202-1210.
Stevenson HW and Lee SY. 1990.Contexts of achievement: a study of American, Chinese, and Japanese children. Monogr Soc Res Child Dev. 55(1-2):1-123.
Sutherland SL and Friedman O. 2013. Just pretending can be really learning: children use pretend play as a source for acquiring generic knowledge. Dev Psychol. 49(9):1660-8.
Sutherland SL and Friedman O. 2012. Preschoolers acquire general knowledge by sharing in pretense. Child Dev. 83(3):1064-71.
Walker CM and Gopnik A. 2013. Pretense
and possibility--a theoretical proposal about the effects of pretend
play on development: comment on Lillard et al. (2013). Psychol Bull. 139(1):40-4.
Wolfgang, Charles H.; Stannard, Laura L.; & Jones, Ithel. (2001). Block play performance among preschoolers as a predictor of later school achievement in mathematics. Journal of Research in Childhood Education, 15(2), 173-180.
Wyver SR and Spence SH. 1999. Play and divergent problem solving: Evidence supporting a reciprocal relationship. Early Education and Development, 10(4): 419 - 44.
Content last of the "Cognitive benefits of play" modified 2/2014
Image of Yaohnanen children playing by Choguet / wikimedia commons