Anthropologists at Dartmouth College, studying the fossil record of primates and early humans, along with the effects of play on child development, found that risk-taking play boosts confidence, internal motivation and risk assessment. Thrill-seeking play confers physical benefits like better dexterity, skeletal muscle development, and physical awareness, all benefits that last into adulthood. The childhood impulse to test physical boundaries through play harks back to our lineage of tree-dwelling primates, whose lifestyles required confidence in physical skills to survive, especially in swinging and climbing.
These anthropologists' work recently substantiated a hundred-plus-year-old proposal when the jungle gym and monkey bars were invented in 1902 and implemented in the progressive education system of the Chicago suburbs. Ted Hinton, the inventor and patent-holder, used 'evolutionary reasoning' as support for the utility of the inventions. His was the first patent in US history to utilize our ancestral history as a prescription for the development and utility of a modern invention.
The benefits of early thrill-seeking play balance with the accompanying injury rates: monkey bars specifically account for 7% of forearm fractures in children. These types of data inspired the recent trend toward ultra-safe playgrounds and the removal of jungle gyms and monkey bars from play structures. The fossil record of early humans or hominids shows a high incidence of healed long-bone fractures like those incurred after a non-fatal fall. The same is true in modern primates, where 21% to 36% of chimpanzees, 20% of gorillas, and 61% of orangutans have suffered non-fatal falls with a resultant long bone fracture, usually of the forearm. Anthropologists have also found that humans and primates alike have the instinct to break a fall with outstretched wrists, another evolutionary development that is shown in the fossil record.
One of the most notable hominids, the famed Australopithecus afarensis "Lucy," likely died from a fall from around 13 m or 43 ft. Lucy's bones were fractured in a way that indicated she had decelerated quickly, likely experiencing a hard landing that fractured her skull. Her injuries were consistent with those found in modern humans who reach their hands out toward the ground to break a fall: greenstick fractures across both forelimb bones, the radius and the ulna. Lucy suffered fractures in both of her upper limbs, with a four-part fracture to her right shoulder and a fractured skull. Not only did Australopithecines experience the occasional fall from a great height, but they more frequently fell from lower heights, where individuals exhibit multiple healed fractures. The prevalence of forearm fractures in hominids indicates that parents of the past did not have the luxury of preventing climbing and falling, an intrinsic part of their niche.
Juvenile chimpanzees spend 27% more time climbing and swinging, and that same trend exists in human children compared with their parents. So, forearm injury is something the species and its ancestors have sustained and successfully withstood for millennia of evolution. The Dartmouth study proposes that the benefits of this outweigh the costs, arguing that our limbs heal quickly and completely, from low- to moderate-height falls, especially as juveniles. Fossil records, as well as contemporary pediatric data, demonstrate that broken forearm bones routinely heal completely. Additionally, preventing children from exploring their physical boundaries, assessing risk on their own, and testing their physical skills in an otherwise safe environment may have worse effects on their well-being than a broken bone. This aspect is not as easily quantified but has the backing of mounting data on the lasting psychological benefits of risky and rough-and-tumble play.
Psychological benefits of risky play
Anthropologists have compiled and reviewed a century's worth of data concluding that risky and thrill-seeking play is essential not only to physiological development but also to positive psychological development of coping skills, building confidence and resilience, and improving risk perception. As children test physical limitations through play, they receive instant feedback on their capabilities and risk assessments. This direct learning differs from acting or learning in response to parenting warnings of "too high," "slow down" or "be careful" that externally indicate to a child that their initial judgment may be flawed. The study reports that when children learn through experience, they gain confidence in their physical abilities and mental assessments.
The Dartmouth researchers concluded that too little risk in a child's play environment hinders coping mechanisms by stifling their innate ancestral drive to explore and test physical boundaries. Children engaging in thrill-seeking play, i.e., the monkey bars or tree-climbing, not only gain confidence in short time frames during childhood but also experience less anxiety and better coping skills as adults. A study undertaken during the 2020 COVID-19 lockdowns demonstrated that children who spent more time in thrill-seeking play exhibited positive behavior symptoms and were less prone to nervousness, worrying, fearfulness and negative social interactions. Scientists link the positive impact of early vigorous exercise and risky play with a strong 'internal locus of control,' meaning that the child develops a belief that their own actions impact the trajectory of their lives more than external events or circumstances, an internal driver that has a huge positive impact on mental health both in childhood and adulthood.
Other studies have documented the cognitive and emotional benefits of engaging in different types of play, like when children wrestle with a father figure specifically. The child's oxytocin levels mimic that of the parent with whom they are interacting, and both dad and child experience an increase in oxytocin during rough-and-tumble play.
Physical benefits of risky play
Thrill-seeking play has been documented as a source of joy and also increases overall physical activity during playtime. The Dartmouth data review found that playgrounds with equipment that tests a child's abilities stimulated 12% more vigorous activity in the children visiting them. Additionally, children with regular access to this type of play and playground equipment showed improved motor skills, dexterity, balance, and coordination over those who did not have access. Other studies cited have shown that risky play helps prevent injury as children sharpen their perceptions of risk in a play scenario. Anthropologists have also found that children as young as four heed their own internal cues for risk, meaning they show caution when approaching playground equipment that exceeds their physical ability. Lastly, the more vigorous activity that is inspired by thrill-seeking play enhanced the bone density in children by about 5-10% when benchmarked at ages 5, 8, and 11. Similarly, gymnasts and climbers, who work out in ways that especially load the arm muscles, retain higher-density bone into adulthood, decades after their training ends.
Simply put, a fall can cause injury, and injury to their children is something human parents often feel that they can or should prevent. However, the risk of not allowing a child to explore this ancestral drive to find out his or her limits and the long-term psychological effects of removing thrill-seeking catalysts like the monkey bars is only now beginning to be understood as a possibly greater one than a broken bone that will heal. This study aims to re-open the debate on the appropriate balance between these two factors.