Volume 2, Number 3

Editor's Note

Welcome to the American Journal of Play special issue on the science of play, the first of a number of theme issues that will appear from time to time. Each will focus on an important topic in the fast-developing study of play. Each will be guest edited by a distinguished expert on the topic. And each will include work by the leading researchers and thinkers on the topic. In this issue, guest-editor Stephen M. Siviy has assembled a series of articles on the scientific study of play as pioneered by Jaak Panksepp (who is interviewed in the issue). These include a seminal article on laughing rats written by Panksepp and Jeffrey Burgdorf and reprinted here for ease of reference as a historical backdrop to the other pieces in this issue. They begin with an article written by Sergio M. Pellis, Vivien C. Pellis, and Heather C. Bell on the subcortical brain mechanisms involved in play. Our guest editor himself contributes a piece exploring the impact of fear and anxiety on play in laboratory animals. Louk J. M. J. Vanderschuren investigates how the brain makes play fun. And Gordon M. Burghardt reviews the growing information on play in species other than our own. A topic not without its controversy, the science of play has been reshaping the landscape for our understanding of play—where it comes from and how it affects us.



Jaak Panksepp, known best for his work on animal emotions and coining the term affective neuroscience, investigates the primary processes of brain and mind that enable and drive emotion. As an undergraduate, he briefly considered a career in electrical engineering but turned instead to psychology, which led to a 1969 University of Massachusetts PhD dissertation examining how electrical stimulation of brain regions affects aggressive behavior. Since then, Panksepp has written more than three hundred articles in scientific books and journals, along with the pathbreaking 1998 study Affective Neuroscience, in which he detailed the neurology, neuroanatomy, neurochemistry, and functions of the emotional brain. For Panksepp and his students, studying play in animals opens a window into what they and other thinkers have come to call the BrainMind or MindBrain. He discovered that rats chirp (“laugh”) during their rough-and-tumble bouts and that play deprivation is a potent motivator akin to thirst or hunger. Optimal brain development depends on healthy play experiences in early life, Panksepp contends, and he observes that over the long evolutionary haul, play has promoted social bonds and nourished social learning. Currently, Panksepp is Baily Endowed Chair of Animal Well-Being Science in the College of Veterinary Medicine at Washington State University; Distinguished Research Professor Emeritus of Psychobiology, Bowling Green State University; and Head, Affective Neuroscience Research, Falk Center for Molecular Therapeutics, Northwestern University. In this wide-ranging interview, Panksepp notes how play shaped his own experience, discusses his life’s work and the context within which he conducted it, and presses for greater recognition of the value of play in psychological research.


by Gordon M. Burghardt


Scholars interested in play in humans should take note of the growing literature on play in other species, especially in light of the application of evolutionary approaches to virtually all areas of psychology. Although most research on animal play deals with mammals—particularly rodents, carnivores, and primates—studies have recorded play of different types in a wide range of other animals, both vertebrate and even invertebrate, who differ greatly in their ecology, their behavior, and their nervous systems. How we characterize such diverse forms of play shapes how we pose research questions and evaluate evidence about play in all species, including humans. In this article, the author reviews the research about play across major taxonomic divisions and looks at the questions that arise when anthropocentric views of play are set aside in order to understand play more broadly. The author then considers how this knowledge illuminates the diversity of play among humans, whom he sees as on the edge of evolutionary change. The article concludes that an understanding of the evolutionary and comparative diversity of play may have implications for integrating play into education and into other attempts to solve ills in society.

by Louk J. M. J. Vanderschuren


In this article, the author describes the empirical studies that have investigated whether play (mostly social play) is rewarding. He then discusses the brain circuits and neurotransmitters that underlie the pleasurable aspects of play. He concludes that the pleasure of play has the ability to reinforce learning activities and that the brain’s neurotransmitters and the brain regions that are deeply involved in motivation and pleasure also mediate the pleasures and motivations that social play produces.

by Sergio M. Pellis, Vivien C. Pellis, and Heather C. Bell


Rough-and-tumble play, or play fighting, is common in the young of many mammals. Research on play fighting among rats shows that there are many levels of neural control over this behavior: subcortical mechanisms mediate the motivation and behavior of such play, and the cortex provides mechanisms by which the play changes with age and context. The cortical mechanisms help to explain the advantages playing offers the brain. The cortically induced modulations of the content of play with age ensure that exposure to particular kinds of experiences are enhanced during the critical juvenile period. These experiences, in turn, modify the development of other areas of the cortex. Such cortical changes appear to mediate the effects of play on the refinement of social skills. As a result, rats that play as juveniles are more socially competent as adults. This work was supported by the Natural Sciences and Engineering Research Council of Canada and the Alberta Heritage Foundation for Medical Research.

by Jaak Panksepp and Jeffrey Burgdorf


In this reprint of a seminal article, once considered quite controversial, the authors discuss their radical claim that rats laugh. Even more provocative, the authors found that this rat-joy sound, especially evident during play, could be amplified dramatically by what they formally call heterospecific (cross-species) handplay (tickling). The authors tickled rats during the most playful juvenile period of their development (older rats sometimes resisted tickling), then studied the ultrasonic chirping the rats produced in response. When analyzed, these vocalizations, occurring during playful rough-and-tumble bouts, suggested analogies to human laughter. The authors also found that fear inhibits playfulness and precludes laughter in rats: sudden, startling bright lights and rough handling reduces the chirping, but even more than these, the smell of a predator’s urine suppresses rat “laughter.” The similar positive emotional responses evident in humans and rats suggests a shared brain anatomy and similar neurochemistry, which, in turn, suggests new ways to investigate the ancient origin of human laughter. This article was the first publication to summarize the full set of groundbreaking experiments that changed the way many researchers and scholars consider animal feelings, human nature, and the field of play.

by Stephen M. Siviy


Most mammals play, but they do so in a dangerous world. The dynamic relationship between the stresses created by their world and the activity of play helps to explain the evolution of play in mammals, as the author demonstrates in evidence garnered from experiments that introduce elements of fear to rats at play. The author describes the resulting fearful behavior and quantifies the fluctuation in play that results, and then he investigates how these are modified by increased maternal care or the use of benzodiazepines. In conclusion, he discusses how such research can help shed light on the neurobiology underlying human anxiety disorders, especially in children.

Book Reviews

by Greta A. Niu

This collection of nineteen essays provides a helpful overview of several media—live-action films, manga (graphic novels), video games, and film and television anime (animation)—including such related commercial products as collectors’ cards and Hello Kitty items and their appearances in Japan and the United States. Interspersed throughout are some anecdotal essays relating experiences with Japanese media, and within the analytical pieces, several authors confess to being fans themselves as children and as adults.

by Susan Asbury

While the title may lend itself to the assumption that this is a book about Ruth Handler and the invention of the Barbie doll, author Robin Gerber provides a much more detailed historical account of the founding of the Mattel Toy Company, Ruth Handler’s role in the company, the development of the world’s most iconographic doll, and Handler’s fall from grace amid a probing investigation by the Securities and Exchange Commission (SEC). Gerber presents her work as a nicely interwoven biography and business history of both Ruth Handler and Mattel. The author looks at Handler’s early life and childhood in Colorado, her move to California in the 1940s, and her courtship, marriage, and business partnership with her soul mate, Elliot Handler. The Handlers founded Mattel in the 1940s, first as a Lucite picture-frame company before venturing into the toy business with the Uke-A-Doodle ukulele. Gerber explores Mattel’s move to toy manufacturing and the struggles both Handlers faced, particularly Ruth, balancing a career and a family. The author analyzes Mattel’s early marketing and production strategies and the financial woes of this start-up company. Through all of this stood Ruth Handler, portrayed by the author as a strong-willed, motivated, and savvy marketer and businesswoman. She was not afraid of trying new ideas, nor did she dwell on the company’s early failures. By the 1950s, Gerber argues, Mattel began to make strides in the industry by reusing popular technology, such as a voice box mechanism, in a variety of toys and by gambling on a major advertising promotion on The Mickey Mouse Club television series, a move that shifted the entire industry towards marketing toys year round instead of the traditional time in the weeks before Christmas. Handler viewed this move as one of the best decisions the company ever made, and it provided a national platform for the introduction of the Barbie doll.

by Doris Bergen

In his introduction, Anthony D. Pelligrini explains his purpose is to write “an academic book” (p. 3), and that his perspective is influenced by his own scholarly experiences and research interests. These, he states, have been guided by an orientation informed by evolutionary theory related to the role of play, by the extensive body of research on animal play, and by his own research. He suggests that much of the play research focused on the play of human children and on the role of play in educational practices has not been especially fruitful. He says that the research, in fact, may have used questionable research criteria and may have made unwarranted assumptions. Thus, his perspective is one that attempts to bring the extensive information about the evolutionary context of both nonhuman and human play together with the more standard theoretical approaches used in early-childhood research on play. He hopes this different perspective will have positive consequences on both child-development research and educational policy decisions. While this is an ambitious goal, readers may find that both the density of his writing and his segues into a number of more esoteric research areas within certain chapters together make it difficult to gain the integrated perspective Pelligrini seeks.

by David Kuschner

Our culture seems to have a love-hate relationship with the act of playing. On the one hand, we value our leisure time and can devote many hours to such activities as golfing or watching our kids play soccer. As parents, we support the toy industry with billions of dollars, and as sports fans, we spend similar amounts of money supporting our favorite teams and athletes. Yet at the same time, we will equate play with frivolity; we accept the reduction of playtime in school in favor of more hours for academics and testing, and we often utter these two telling expressions: “Stop playing, and get down to work” and the dismissive “Oh, he’s just playing.”

by Gordon M. Burghardt

The last several years have seen an enormous growth of interest in many aspects of animal cognitive and emotional capacities. Animals, it has been shown, can learn to solve problems by observing others, can experience complex emotions, and can communicate with others about resources and danger, sometimes deceptively. Dogs and parrots can understand the meaning of human words, and chimpanzees can solve memory-retrieval tasks at rates faster than most people. Nonetheless, those committed to an essential discontinuity between the human and nonhuman often point to the supposed lack of moral and ethical behavior among animals. Although many humans pay attention to our ethical responsibilities to other species, no one has much studied whether other species have moral and ethical codes that may operate in their lives and serve as evolutionary precursors to the purportedly advanced moral behavior of human beings.

by Jeff Bowersox

If you believe the German toy industry’s own hype, around the turn of the twentieth century it had cornered 60 percent of the world market and dominated its own domestic market. Even if you are skeptical about these particular numbers, it is certainly true that German toy makers were the most successful toy exporters in the world and profited more from foreign consumers (above all in America and Britain) than from their compatriots. Given these sorts of connections, developments in Germany take on particular relevance for anyone interested in the changing nature of childhood and play in Europe and North America before World War I. Fortunately, we have in David Hamlin’s and Bryan Ganaway’s recent studies—both revised versions of their dissertations—good surveys of the development of the German toy industry and the cultural associations surrounding its products. Both use toys to illustrate the nexus of mass consumption, rising middle-class ideals, and changing notions of childhood that have been the focus of much recent research. Their works also implicitly suggest the value of a more holistic, transnational approach to the history of play and childhood.

Gordon M. Burghardt is Alumni Distinguished Service Professor in the Departments of Psychology and Ecology and Evolutionary Biology at the University of Tennessee, where his primary research focuses on the relationship between genetics and early environments in the development of behavior patterns and sensory processes. He is the author of The Genesis of Animal Play: Testing the Limits and numerous scientific papers, editor of the Journal of Comparative Psychology, and a member of the editorial boards of four other journals. He has been a fellow at the American Psychological Association, American Psychological Society, Animal Behavior Society, and the American Association for the Advancement of Science.

Jaak Panksepp is distinguished Research Professor Emeritus of Psychology at Bowling Green State University, Baily Endowed Chair of Animal Well-Being Science at Washington State University’s College of Veterinary Medicine, and head of Affective Neuroscience Research at the Falk Center for Molecular Therapeutics at Northwestern University. He is editor of the Textbook of Biological Psychiatry and author of Affective Neuroscience: The Foundations of Human and Animal Emotions. In addition, he has written more than three hundred articles in the fields of psychology and affective neuroscience. Jeffrey Burgdorf is a Post-Doctoral Research Associate in the Department of Biomedical Engineering at the Falk Center for Molecular Therapeutics at Northwestern University. His numerous scientific papers have appeared in, among other places, Behavioral Neuroscience, Psychopharmacology, and Consciousness and Emotion.

Sergio M. Pellis is a Professor and Principal Investigator at the University of Lethbridge Canadian Centre for Behavioral Neuroscience. He has written and lectured extensively on play behavior in rodents and primates; contributed articles and chapters to many journal and books; and is coauthor of Playful Brain: Venturing the Limits of Neuroscience (2009), which encompasses three decades of empirical research supporting an integrated study of the multifunctionality of play and the differences that exist between the species. Vivien C. Pellis serves as Assistant Professor and postdoctoral fellow at the University of Lethbridge Canadian Centre for Behavioral Neuroscience. Her research interests include play behavior in animals and humans, autism, and righting reflexes, and she is coauthor of Playful Brain: Venturing the Limits of Neuroscience, as well as numerous other publications. Heather C. Bell is a doctoral candidate at the University of Lethbridge. Under the direction of Sergio M. Pellis, she is working on computational models of interacting systems of organisms. Bell’s coauthored articles have appeared in Behavioral Neuroscience and Behavioural Brain Research.

Stephen M. Siviy is Chairperson of the Psychology Department at Gettysburg College. His primary research interest is in identifying neurobiolical substrates of mammalian playfulness. With more than twenty years of experience in the field, Siviy’s coauthored articles have appeared in, among others, Behavioural Brain Research, Neuroscience & Biobehavioral Reviews, Journal of Comparative Psychology, and Behavioral Neuroscience. Siviy also served as a postdoctoral fellow at the University of Sydney and the University of California, Los Angeles.

Louk J. M. J. Vanderschuren is Associate Professor at the Ruldolf Magnus Institute of Neuroscience of the University Medical Center Utrecht in the Netherlands. He investigates the neurobiology of social behavior, impulsivity, and addiction, and his many papers have appeared in publications such as Science, Nature Medicine, the Journal of Neuroscience, and Biological Psychiatry. He also serves as Associate Editor of Behavioural Phamacology, published in association with the European Behavioural Pharmacology Society.