Andrew Huberman explains the neuroscience and lifelong importance of play
A solo episode of Huberman Lab Essentials in which Stanford neuroscientist Andrew Huberman explains the biology, psychology, and practical utility of play across the lifespan.
Summary
Andrew Huberman, professor of neurobiology and ophthalmology at Stanford School of Medicine, presents a deep dive into the science of play — arguing that it is not merely a childhood activity but a lifelong neurological necessity. He explains that play is driven by the release of endogenous opioids from the periaqueductal gray, a brainstem region, which in turn frees the prefrontal cortex to explore a broader range of behavioral possibilities. The central mechanism Huberman identifies is low-stakes contingency testing — trying out different roles and outcomes in an environment where adrenaline remains low — and he argues this is the most powerful portal to neuroplasticity at any age, with emerging evidence (at this point largely anecdotal) that adults who maintain a playful stance experience more ongoing cognitive flexibility. He draws on peer-reviewed research, personal anecdotes, and examples ranging from animal play postures to chess and Richard Feynman's lifelong tinkering to make the case that play retains profound value across the entire lifespan.
A significant portion of the episode addresses personal play identity — the idea that the way a person played between ages 10 and 14, including their comfort with leadership versus following, competition versus cooperation, rule flexibility, and group versus solo play, directly shapes how they show up in adult work, relationships, and social hierarchies. Huberman also uses the extended anecdote of childhood 'dirt clod wars' to illustrate how rule-breaking within play teaches children (and adults) about social norms, stakes calibration, and group dynamics.
Key Takeaways
FULL TRANSCRIPT
What Play Is and Why It Matters
Andrew Huberman: Today we are going to talk about the biology, psychology, and utility of play. Much of our childhood development centers around play, whether it's organized or spontaneous. But as adults, we also need to play. Let's talk about what I like to refer to as the power of play.
What is the utility of play? Why do we play when we're younger? Why do we tend to play less as we get older? And what in the world is play for?
As we'll learn, play is generated through the connectivity of many brain areas, but one of the key brain areas is an area called PAG — the periaqueductal gray. The periaqueductal gray is a brainstem area, so it's pretty far back, where the brain transitions into the spinal cord. It's rich with neurons that make endogenous opioids. These are not the kinds of opioids that are causing the opioid crisis. These are neurons that you and I all have that release endogenous — meaning self-made or biologically made — opioids. They go by names like enkephalin and things of that sort.
Play evokes small amounts of opioid release into the system. That turns out to be a very important chemical state because there's something about having an abundance of these endogenous opioids released into the brain that allows other areas of the brain — like the prefrontal cortex, the area at the front responsible for what we call executive function — to operate differently. Executive function is the ability to make predictions and to assess contingencies: if I do this, then that happens; if I do that, then this other thing happens.
The prefrontal cortex is often seen as a kind of rigid executive of the whole brain. That's one way to view it. But probably a better way to view it is that the prefrontal cortex works in concert with these other, more primitive circuitries. And when the periaqueductal gray releases these endogenous opioids during play, the prefrontal cortex doesn't get stupid — it actually gets smarter. It develops the ability to take on different roles and explore different contingencies.
So much of play is really about exploring things in a way that feels safe enough to explore. What I'd love for everyone to do is stop thinking about play as just a child activity or just a sport-related activity, but really as an exploration of contingencies — an exploration of: if I do A, what happens? If I do B, what happens? If someone else takes on behavior or attitude C, what am I going to do? Play is really where we can expand our catalog of potential outcomes. And it can be enormously enriching. The tinkerers of the world, the true creatives, the people who build incredible technologies and art, and who also just have incredibly rich emotional, intellectual, and social lives, all have a strong element of play.
The Core Rules of Play
Many of us, including myself, haven't played that much as adults. But as children, most all of us engaged in a lot of play. And in looking at the way that very young children — especially toddlers — play, we can learn a lot, because it reveals the fundamental rules by which the toddler brain interacts with the world.
There are hundreds of different types of play and hundreds of different types of contingency testing, but the key theme is that play allows children, and adults for that matter, to explore different outcomes in a kind of low-stakes environment. Play is contingency testing under conditions where the stakes are sufficiently low that individuals should feel comfortable assuming different roles — even roles that they're not entirely comfortable with in their outside life.
That all relates again to the release of these endogenous opioids in the periaqueductal gray and the way that it allows the prefrontal cortex, in a very direct biological way, to expand the number of operations it can run. And it starts thinking: normally I'm kind of a loner who likes to read and work and maybe even play alone, but okay, I'll play a board game or a game of tennis where I have a partner and we're going to play as partners against two other people. That's a little uncomfortable, but I'll do it. And in doing that, you discover certain ways in which you are proficient and certain ways in which you are less proficient. You discover that the other person actually tends to cheat a little bit, or the other person is extremely rigid about the rules, or maybe extremely rigid about how they organize their pieces on the board or about crossing the line into your side of the tennis court.
There are all sorts of things we learn in these rather low-stakes scenarios. That's the key theme.
A Tool for the Less Playful
Before I continue, I want to point to a tool that anyone can use, but in particular those of us who are less playful. I would put myself in that category. What I'm about to tell you is that anyone and everyone can benefit from engaging in a bit more of this playful mindset. It's really about allowing yourself to expand the number of outcomes you're willing to entertain, and to think about how you relate to those different outcomes.
What this means practically is putting yourself into scenarios where you might not be the top performer — playing a game you're not really that good at. I had this experience recently. I have friends who like to play cards, who like to do some low-stakes gambling, and I generally don't buy into the game. I generally don't play, mostly because they end up winning and taking whatever I have. But in the mode of assuming a more playful spirit, the idea is that if the stakes are low enough, you play simply for the sake of playing, because there's something to learn there about the other people in the group and about yourself — how you react to someone who's clearly trying to take everybody's money, or somebody who is clearly trying to cheat, or somebody who's very rigid about every last detail including how the cards are dealt and shuffled.
There is learning in this exploration. You can immediately see how just a small increase in your willingness to put yourself into conditions where you don't understand all the rules, or where you're not super proficient, but you enter it because it is low stakes and because there is information to learn about yourself and others — how that could start to open up these prefrontal cortex circuits.
When I say open up, I don't mean literally there's an opening in your skull. What I mean is that your prefrontal cortex can work in very rigid ways — if A, then B. If I go down this street and turn left, it's fast. If I go down the other street, it's slow. But play is about starting to explore different possibilities, and there are very few opportunities in life to explore contingencies in this low-stakes way such that it engages neuroplasticity of the prefrontal cortex.
Play is powerful at making your prefrontal cortex more plastic — more able to change in response to experience — not just during the period of play, but in all scenarios, because you get one prefrontal cortex. You don't get a prefrontal cortex just for play. You get one prefrontal cortex that engages in everything.
Play Postures in Animals and Humans
Another really interesting and important aspect of play is so-called play postures. These are seen in animals and in humans. Perhaps the most familiar one is seen in dogs and wolves, where they will lower their head to the ground, put their paws out in front of them, and make eye contact with another dog or wolf to call the play. When they do this posture, it's obvious that they're lowering themselves — they're not in an aggressive stance because they're lowering their head. This is universally known among canines as play posture.
Humans do this as well, although in a different form. More typically, when humans want to play, they will do a subtle or not-so-subtle head tilt. The head tilt with eyes open is considered the universal head and facial expression posture of play in humans. When two people see one another, if they are aggressive toward one another, they will assume certain facial expressions and postures. But if they're feeling playful, often they'll tip their head to the side just a little bit, open their eyes, and might even raise their eyebrows briefly.
Another hardwired feature of play postures is what's called soft eyes. When animals are aggressive or sad, they tend to reduce the size of their eye openings by keeping their eyelids closer together. For aggression in particular, they'll bring their eyes toward what we call a vergence eye movement — toward the center — which actually narrows the aperture of the visual field. When people or animals want to engage in play, they tend to open their eyelids somewhat and purse their lips just a little bit, often doing the head tilt as well, sometimes with a slight smile.
We also see what are called partial postures. These are a kind of play enactment of postures that would otherwise be threatening. A partial posture we see during rough-and-tumble play in animals and kids and some adults is this: because there's going to be a physical interaction, animals will march toward one another, often very slowly, but rather than having their hair up — which we call piloerection, when the hair goes up to make themselves look bigger — they will keep their fur down. Humans will do this too: they approach during play, but unless it's highly competitive play like a football game or a boxing match, they will actually shrink their body size somewhat.
Learning Social Rules Through Play
The failures to do this are very informative in how we develop in social groups, and can inform why some people play well with others and other people don't, and why some people can handle group dynamics while others are very rigid.
I have an anecdote about this. When I was a kid, we used to play what were called dirt clod wars. A friend of mine whose parents were generally not home in the afternoon — we must have been around 10 or 11 years old — and we would shovel two big dirt mounds on two sides of the yard and just throw dirt clods at one another. But there were rules: you couldn't pack rocks into the dirt clods, you could run across to the other side and jump on the other person's mound, and if someone got hit in the head, there was an unspoken rule that you kind of stopped and checked whether they were okay before continuing. You couldn't just keep pelting them.
Of course, people broke this rule. I remember one kid — I'm not going to name him because he's actually grown into a very prominent and functional adult — but he got hit once in the head, and then someone threw another dirt clod shortly thereafter, and he just went into a rage, picking up rocks and sticks and attacking another kid. That was a case where the rules of the game were being violated. The idea is that there's an agreed-upon set of rules about how high the stakes are and what we're all going to do. This is separate from organized sport, where there are clearly defined rules about what's out of bounds and what behaviors will get you a yellow card or a red card on the soccer field.
All animals, including humans, are doing this low-stakes contingency testing. And all animals, including humans, will start to up the stakes. Inevitably in group play, one member of the group will kind of break the rules. So we could all look at our adult counterparts, and indeed we should look at ourselves, and ask: did we learn proper play contingency when we were younger? Do we tend to take things too seriously? Do we tend to overreact aggressively when other people are clearly engaging in playful jabbing or sarcasm?
Each of you will have a different experience of this, but the point is that play serves many functions. It's not just about the self — it's also about interactions between multiple people. It's about rule testing and low-stakes contingency. Rule breaking also serves an important role, as in the example of the dirt clod war. And last but not least, there are different forms of play that help us establish who we will become as adults.
Role Play and the Prefrontal Cortex
One of the more powerful forms of play is role play — when children and sometimes adults take on different roles that are distinct from their natural world roles, in order to establish hierarchies. Someone's going to be the leader and someone's going to be the follower. Someone will work alone, others will work in a group. These kinds of role-playing exercises are ways in which the prefrontal cortex has to expand the number of operations — in neuroscience we call these algorithms — that it has to run in order to make predictions. You have to take in a lot of information about your environment all the time and make predictions. But if you're suddenly cast into a new role, you definitely have to make even more predictions from a different standpoint. These experiences are very powerful for teaching the brain how to function.
What I'm hoping is coming through here is that play is not just about having fun. Play is about testing, experimenting, and expanding your brain's capacity. That's true early in development and it's true throughout the lifespan.
The Neurobiology and Neurochemistry of Effective Play
At this point I want to take a step back and look at the biology and neurochemistry of play just a little bit more, and in doing that really define what effective play is. If the goal of play is to explore different contingencies in low-stakes environments and to expand the function of our prefrontal cortex so that we can see new possibilities and new ways of being — become more flexible, more creative, more effective outside of the arenas of play — then we should be asking: how do I know if I'm playing? How do I know if I'm playing correctly?
Turns out there's an answer to that. Earlier I referred to the periaqueductal gray, which releases endogenous opioids into our brain and body and tends to relax us a bit. It actually is what leads to things like soft eyes and head tilts and puppies making play postures, and it's how that opens up the number of different functions or algorithms the prefrontal cortex can run.
But there's another piece of the puzzle. For something to genuinely be play — and for it to have the effect of expanding our brain and engaging neuroplasticity, of really changing our brain so that we can see and engage in more possible behaviors and thoughts — we also have to have low amounts of adrenaline, so-called epinephrine, in our brain and body.
The background science for this is quite extensive, but for those interested in papers and manuscripts, perhaps the best one is a review published in Neuroscience and Biobehavioral Reviews by Jaak Panksepp, with co-author Steven Siviy — S-I-V-I-Y — and the title is "In Search of the Neurobiological Substrates for Social Playfulness in Mammalian Brains." It's quite extensive, but it basically boils down to some key findings: any sorts of drugs or behaviors or scenarios that increase levels of adrenaline too much will tend to inhibit play, while drugs and scenarios that increase the endogenous opioid output will tend to increase playfulness.
So the state of mind one needs to adopt when playing is this: you have to engage in the play with some degree of focus and seriousness — focus and seriousness in the neurobiological context generally means epinephrine, and the presence of dopamine, which is a molecule that generates motivation and focus — but also that these endogenous opioids be liberated. It's really the low-stakes feature of play that allows those endogenous opioids to be liberated.
What do I mean by that? If you are very concerned about the outcome — you've put a lot of money on the table, or you're a football player in the Super Bowl, or you're playing a game for which winning is absolutely crucial to you — well then that's not really going to engage the play circuitry. On the contrary, if you're engaging in those same behaviors or any other behavior in a way that you're simply there to explore, without high levels of adrenaline and not stressed about the potential outcome — that constitutes play.
Now, that's somewhat obvious on one hand: you take seriously what you take seriously, and you can be more playful about things you don't take so seriously. But what is absolutely not obvious is that the state of playfulness is actually what allows you to perform best. Because the state of playfulness offers you the opportunity to engage in novel types of behaviors and interactions that you would not otherwise be able to access if you are so focused on the outcome.
Play as the Most Powerful Portal to Plasticity
For all of us thinking about tools and things we can extract from science to enrich our lives: for those of you that are already playing on a regular basis in one form or another, terrific. Start to expand into other forms of play, in particular forms that involve new groups of individuals. This is the way that your brain learns and evolves and changes and gets better.
One of the top questions I get is: "How can I keep my brain young? How can I continue to learn? How can I get better in school, in sport, in life, in relationships — emotionally, cognitively?" Yes, there are brain games and apps that can support neuroplasticity. But if you really want to engage neuroplasticity at any age, what you need to do is return to the same sorts of practices and tools that your nervous system naturally used throughout development and that evolved over hundreds of thousands of years to trigger neuroplasticity. Play at every stage of life is the way in which we learned the rules for that stage of life, and play is the way in which we were able to test how we might function in real-world contexts.
Play is powerful, and we could even say that play is the most powerful portal to plasticity. The reason is that the high-opioid, low-epinephrine state is what opens up play. Then inside the arena of play, when the prefrontal cortex is running all these different possibilities in this low-stakes way but with some degree of focus, a number of other chemicals are deployed — things like brain-derived neurotrophic factor and other growth factors that actually trigger the rewiring of brain circuits, allowing them to expand. That is neuroplasticity.
Thus far, I've tried to convince you through a combination of data, anecdote, and explanation that adopting a stance of playfulness and engaging in play on a somewhat regular basis could be beneficial regardless of your circumstances or goals. There's even some evidence — at this point largely anecdotal, but with data starting to emerge — that adults who maintain a playful stance, who engage in things that are low-stakes contingency exploration where people focus and pay attention but are not filled with adrenaline and freaked out about the outcome, experience more ongoing plasticity.
Richard Feynman and the Playful Mind
One of the people who comes to mind here is the physicist Richard Feynman — Nobel Prize winner, professor at Caltech, involved in the Manhattan Project, but also known as a lifelong tinkerer and a mischievous one at that. If you read any of the books about Feynman or by Feynman — Surely You're Joking, Mr. Feynman or What Do You Care What Other People Think? — these are wonderful short stories mostly about Feynman doing things like picking all the locks at the Los Alamos Laboratory and putting all the top secret documents out on the floor of the office so that when people came in in the morning, they were all laid out there. He obviously wasn't releasing them to the general public or trying to threaten national security.
In some of his writings, he pointed to the fact that this playful spirit was something he worked very hard to continue cultivating in himself, because it was the way in which he could see the world differently and make great discoveries in the field of physics, but also to evolve his relationship to life more generally. He comes to mind as a prominent example of somebody who did this.
If I could achieve anything with this episode besides teaching you something about the biology of play, it would be to teach you about the utility of play. Again, I don't consider myself a particularly playful person by nature. But I've tried over the years to adopt this stance of exploring things that are focused on contingencies of different kinds while keeping the stakes low enough that I can have some fun doing them. I like to think it's benefited me somewhat.
Forms of Play That Best Support Neuroplasticity
Now I'd like to drill a little further into neuroplasticity specifically. There are particular forms of play that lend themselves best to neuroplasticity — not just to improve your performance at that specific activity, but to expand the number of possibilities for your brain to change in general throughout life.
The two major forms for which there is good peer-reviewed research are: first, engaging in novel forms of movement including different speeds of movement. If you're somebody who runs, running doesn't lend itself to a lot of novel forms of movement — lateral movement, or angled movements. But things like dance or sports where you generate a lot of dynamic movement — jumping, movement at different angles, ducking, leaping — things that involve dynamic movement and aren't strictly linear seem to open the portals for plasticity. They do this because they mimic a lot of the brain circuitry associated with play, specifically through the way those dynamic movements and movements of different speeds engage the vestibular system — the balance system. The vestibular system is in the inner ear and relates to the cerebellum, which translates to "mini brain." That little mini brain in the back of your brain brings together visual information in a very direct way.
Engaging in play that has a lot of dynamic movement or movements of different speeds — dance, soccer, sports where you're moving in different dimensions — tends to be very conducive to play-related circuitry, provided you don't take it too seriously and you don't get those high levels of epinephrine.
Chess, Role Adoption, and Non-Physical Play
For those interested in non-physical or non-athletic forms of play that can really expand plasticity, there's some very interesting research about the game of chess. There's a nice paper published in the International Journal of Research in Education and Science in 2017, titled "Is Chess Just a Game or Is It a Mirror That Reflects a Child's Inner World?" That's a very intense title for a biologist like me. But this paper is fascinating because what it really points to is the fact that in a single game of chess you have at least two players, and those players are moving pieces for which each piece can do different things — move in different ways under different scenarios — and there are different rules for different pieces. So each player actually has to assume multiple identities during the same game, and each of those identities has different rules and ways of interacting.
In a way, we can think of chess as one game, but actually chess is a substrate for exploring multiple roles for different characters. This is quite different from, for instance, video games where somebody has their favorite player or avatar and they're always in the same role.
For those of you interested in leveraging play for neuroplasticity, I highly recommend picking an activity that will allow you to adopt different roles within that activity — where it's not rigidly linear. This is actually where I start to depart from the modern but somewhat narrow idea that exercise is the only route to plasticity. Play is about dynamically exploring different kinds of movements, different kinds of thoughts, and different kinds of roles — and that is how the brain learns new things.
Personal Play Identity
In researching this episode, one of the most interesting areas I discovered was the notion of personal play identity. There are four components to personal play identity: how you play, your personality, socioculture and environment, and economics and technology.
That sounds somewhat complex, but basically what it says is that we bring together certain aspects of ourselves and how we react to different play scenarios when we're younger, and we carry that forward into the world in all contexts as adults.
To illustrate this, I'm going to ask you a question. When you were a child, let's say 10 years old: would you have considered yourself competitive? Would you have considered yourself cooperative? And realize those are not mutually exclusive. Would you have preferred to play alone, or with one or two close friends, or did you really enjoy playing in large groups? Here's a key one: were you someone who enjoyed playing the leader in one moment and was equally okay with being a follower at a later moment? Were you okay with having your role switched midway through a game? Would you get upset, be delighted, or not care at all about having to switch teams during the middle of a game because your team was winning? You can imagine how that would play out internally — you would immediately register that you must be a valuable player because you're being moved off the winning team toward the losing team. But then again, you're now being forced to join the losing team. How did you feel about that?
The point is that if we look back to our early adolescence — somewhere between 10 and 14 years old, a peak time for social development, for play of various kinds, for motor development, and for psychosocial development where we learn where we fit into hierarchies as we relate to members of the same sex, of the opposite sex, and so on — we can start to get a portal into how and why we show up to various activities in work, in relationship, and so on as adults.
Development as a Lifelong Arc
One of my favorite things about developmental biology and developmental psychology is that it is grounded in the fact that we don't just have a childhood and an adulthood. There isn't just our child self and our adult self. Even though there are transitions around the mechanisms that underlie neuroplasticity at approximately age 25, it is simply the case that development is our entire lifespan — one long developmental arc. How long depends on our genetics, our lifestyle, accidents, injury, and disease, of course, but it is one long developmental arc.
So it shouldn't surprise us at all that how we learn to play as a 10- or 12-year-old would impact how we play and interact with people as a teenager and a young adult and on and on. And that play is the place in which we explore and in which we learn. Play is the substrate by which our nervous system changes us from this hyperconnected batch of neurons where everything is connected to everything more or less, to a brain and nervous system whereby certain circuits work with immense proficiency and others are less accessible to us.
Play is really about not even worrying about whether you're going to get good at something or really proficient at it. It's really about exploring contingencies with truly low stakes. That's what will allow you to access these neurochemical combinations of elevated endogenous opioids and low epinephrine that will open up neuroplasticity.
We have brain circuits from back to front and within our body that are there for play — and they don't disappear. They do not get pruned away as we go from development to adulthood. If ever you needed a neurobiological explanation for why play is important throughout the lifespan, it's this: biology does not waste resources. It's extremely efficient. Were the circuits for play not important in adulthood, they would have been pruned away. But those circuits are there in your brain and nervous system now. They will be there tomorrow and they will be there going forward. My suggestion is that you use them.