The DOI matches its Crossref record; 1 of the 28 references it cites were found in a registry or an index.
The Genesis of Animal Play: Testing the Limits
Open accessAbstract
In The Genesis of Animal Play, Gordon Burghardt examines the origins and evolution of play in humans and animals. He asks what play might mean in our understanding of evolution, the brain, behavioral organization, and psychology. Is play essential to development? Is it the driving force behind human and animal behavior? What is the proper place for the study of play in the cognitive, behavioral, and biological sciences? The engaging nature of play—who does not enjoy watching a kitten attack a ball of yarn?—has made it difficult to study. Some scholars have called play undefinable, nonexistent, or a mystery outside the realm of scientific analysis. Using the comparative perspectives of ethology and psychology, The Genesis of Animal Play goes further than other studies in reviewing the evidence of play throughout the animal kingdom, from human babies to animals not usually considered playful. Burghardt finds that although playfulness may have been essential to the origin of much that we consider distinctive in human (and mammalian) behavior, it only develops through a specific set of interactions among developmental, evolutionary, ecological, and physiological processes. Furthermore, play is not always beneficial or adaptive. Part I offers a detailed discussion of play in placental mammals (including children) and develops an integrative framework called surplus resource theory. The most fascinating and most controversial sections of the book, perhaps, are in the seven chapters in part II in which Burghardt presents evidence of playfulness in such unexpected groups of animals as kangaroos, birds, lizards, and "Fish That Leap, Juggle, and Tease." Burghardt concludes by considering the implications of the diversity of play for future research, and suggests that understanding the origin and development of play can shape our view of society and its accomplishments through history. The open access edition of this book was made possible by generous funding from Arcadia – a charitable fund of Lisbet Rausing and Peter Baldwin.
Overview
Integrity signals
Registry
Cites
Statistics
Verification
Claims the paper makes
Claims other papers make about this one
Each is checked against this paper’s own text: does it say what the citing paper says it does?
In the citing paper
“Social play (also referred to as play-fighting or rough-and-tumble play) is predominantly displayed among juveniles of both sexes across many mammalian species (Bekoff and Byers, 1998; Pellis and Iwaniuk, 2000; Burghardt, 2005).”
From Sex-specific modulation of juvenile social play behavior by vasopressin and oxytocin depends on social context (2014) · cites this paper as Burghardt, 2005
In the citing paper
“Playful contexts produce different types of play (e.g., solitary and/or social play) which are characterized by repeated yet non-stereotypic sequences of behavior (Burghardt, 2005).”
From Play in Rats: Association across Contexts and Types, and Analysis of Structure (2014) · cites this paper as Burghardt, 2005
In the citing paper
“supporting the theory that different types of play may have had independent evolutionary origins and trajectories (Burghardt, 2005).”
From Play in Rats: Association across Contexts and Types, and Analysis of Structure (2014) · cites this paper as Burghardt, 2005
Citations
Cites
Zebra Finches (Taeniopygia guttata )
Law, G., Nager, R., & Wilkinson, M. (2018) · Companion Animal Care and Welfare · doi:10.1002/9781119333708.ch15 · Cited by 3
Cited by
Sorted by citations
Items 301–400 of 1,001
Pellegrini, A. D., & Hou, Y. (2011) · Journal of comparative psychology · doi:10.1037/a0023046 · Cited by 22
Play behavior in immature moor macaques (Macaca maura) and Japanese macaques (Macaca fuscata)
Francés, V. B., Castellano‐Navarro, A., Maulany, R. I., et al. (2020) · American Journal of Primatology · doi:10.1002/ajp.23192 · Cited by 22
Kull, K. (2018) · Biosemiotics/Biosemiotics. Bookseries · doi:10.1007/978-3-319-72992-3_10 · Cited by 22
Senft, G., Östman, J.-O., & Verschueren, J. (2013) · Culture and language use · doi:10.1075/clu · Cited by 22
Learning Latent Plans from PlayPreprint
Lynch, C., Khansari, M., Xiao, T. G., Kumar, V., Tompson, J., Levine, S., & Sermanet, P. (2019) · arXiv (Cornell University) · doi:10.48550/arxiv.1903.01973 · Cited by 222
Serres, A., Hao, Y., & Wang, D. (2020) · Animals · doi:10.3390/ani10060924 · Cited by 22
Let’s unite in play! Play modality and group membership in wild geladas
Gallo, A., Caselli, M., Norscia, I., et al. (2021) · Behavioural Processes · doi:10.1016/j.beproc.2021.104338 · Cited by 21
Hüttner, T., Dollhaeupl, S., Simon, R., Baumgartner, K., & von Fersen, L. (2021) · Animals · doi:10.3390/ani11072107 · Cited by 23
Brains, Behaviour, and Cognition: Multiple Misconceptions
Font, E., Burghardt, G. M., & Leal, M. (2023) · Health and Welfare of Captive Reptiles · doi:10.1007/978-3-030-86012-7_7 · Cited by 24
Self-citationAn improved design for the spatial judgement task in domestic pigs
Düpjan, S., Stracke, J., Tuchscherer, A., & Puppe, B. (2016) · Applied Animal Behaviour Science · doi:10.1016/j.applanim.2016.11.012 · Cited by 21
Pellis, S. M., & Pellis, V. C. (2017) · Journal of comparative psychology · doi:10.1037/com0000082 · Cited by 21
Is Heightened-Shoaling a Good Candidate for Positive Emotional Behavior in Zebrafish?
Franks, B., Graham, C., & von Keyserlingk, M. A. G. (2018) · Animals · doi:10.3390/ani8090152 · Cited by 24
Use of social network models to understand play partner choice strategies in three primate species
Lutz, M. C., Ratsimbazafy, J., & Judge, P. G. (2019) · Primates · doi:10.1007/s10329-018-00708-7 · Cited by 21
Teaching modeling skills using a massively multiplayer online mathematics game
Araya, R., Jiménez, A., Bahamondez, M., Calfucura, P., Dartnell, P., & Soto-Andrade, J. A. (2012) · World Wide Web · doi:10.1007/s11280-012-0173-5 · Cited by 21
“A natural strategy is to use games, since games are a learning mechanism used not only by humans but also by other mammals, birds, and even reptiles [8].”
BackgroundInfluentialDiamond, J., Eason, D., Reid, C. S. W., & Bond, A. B. (2006) · Behaviour · doi:10.1163/156853906778987551 · Cited by 21
Is Play Behavior Sexually Dimorphic in Monogamous Species?
Chau, M. J., Stone, A. I., Mendoza, S. P., & Bales, K. L. (2008) · Ethology · doi:10.1111/j.1439-0310.2008.01543.x · Cited by 21
Beluga (Delphinapterus leucas) novel bubble helix play behavior
Jones, B. L., & Kuczaj II, S. A. (2014) · Animal Behavior and Cognition · doi:10.12966/abc.05.10.2014 · Cited by 21
Timberlake’s theories dissolve anomalies
Killeen, P. R. (2019) · Behavioural Processes · doi:10.1016/j.beproc.2019.103894 · Cited by 19
Early evidence for emotional play contagion in juvenile ravens
Wenig, K., Boucherie, P. H., & Bugnyar, T. (2021) · Animal Cognition · doi:10.1007/s10071-020-01466-0 · Cited by 21
Pons, P., Javier, J., & Catalá, A. (2014) · International Conference on Advances in Computer Entertainment Technology (ACE) · doi:10.1145/2693787.2693794 · Cited by 22
“The reason why animals play has been the focus of many dissertations [5,6] and several studies have used the concept of play as a tool to stimulate animals to participate voluntarily in their experiments.”
BackgroundBlake, B. E., & McCoy, K. A. (2015) · Neuroscience & Biobehavioral Reviews · doi:10.1016/j.neubiorev.2015.04.021 · Cited by 20
Rethinking Children's Participation in Democratic Processes: A Right to Play
Lester, S. (2013) · Sociological studies of children and youth · doi:10.1108/s1537-4661(2013)0000016006 · Cited by 20
Salmonid Jumping and Playing: Potential Cultural and Welfare Implications
Fagen, R. M. (2017) · Animals · doi:10.3390/ani7060042 · Cited by 20
Hormonal Correlates of Exploratory and Play-Soliciting Behavior in Domestic Dogs
Rossi, A., Parada, F. J., Stewart, R., Barwell, C., Demas, G. E., & Allen, C. (2018) · Frontiers in Psychology · doi:10.3389/fpsyg.2018.01559 · Cited by 18
Relationships between play and responses to tickling in male juvenile rats.
Hammond, T., Bombail, V., Nielsen, B. L., Meddle, S. L., Lawrence, A. B., & Brown, S. M. (2019) · Applied Animal Behaviour Science · doi:10.1016/j.applanim.2019.104879 · Cited by 18
Nolfo, A. P., Casetta, G., & Palagi, E. (2021) · Current Zoology · doi:10.1093/cz/zoab076 · Cited by 20
Stark, R. A. M., Ramkumar, R., & Pellis, S. M. (2021) · International Journal of Comparative Psychology · doi:10.46867/ijcp.2021.34.5592 · Cited by 20
Westerlaken, M., & Gualeni, S. (2014) · doi:10.1145/2693787.2693796 · Cited by 20
The Game Frame: Systemizing a Goffmanian Approach to Video Game Theory
Deterding, S., & Medienforschung, H.-B.-I. F. (2009) · Cited by 21
Butler, A. B. (2012) · Advances in experimental medicine and biology · doi:10.1007/978-1-4614-1704-0_19 · Cited by 20
Comparative evolutionary psychology of sperm competition.
Shackelford, T. K., & Goetz, A. T. (2006) · Journal of comparative psychology · doi:10.1037/0735-7036.120.2.139 · Cited by 20
“…not arguing that similarities across wide phylogenetic chasms (such as insects, birds, and humans) necessitate homologous mechanisms, but rather that similar mechanisms may be the products of convergent or independent evolution of solutions to similar adaptive problems (see, e.g., Burghardt, 2005).”
BackgroundAchterberg, E. J. M., Burke, C. J., & Pellis, S. M. (2023) · Behavioural Processes · doi:10.1016/j.beproc.2023.104933 · Cited by 20
Law, C. J., Baliga, V. B., Tinker, M. T., et al. (2017) · Biological Journal of the Linnean Society · doi:10.1093/biolinnean/blw050 · Cited by 19
Park, J., Lee, E.-H., Kwon, H., Baek, I., Seo, J.-S., Kim, K., & Han, P. (2021) · Biological Psychiatry · doi:10.1016/j.biopsych.2021.09.027 · Cited by 19
The face never lies: facial expressions and mimicry modulate playful interactions in wild geladas
Gallo, A., Zanoli, A., Caselli, M., Norscia, I., & Palagi, E. (2022) · Behavioral Ecology and Sociobiology · doi:10.1007/s00265-022-03126-4 · Cited by 19
Controlled Deprivation and Enrichment
Mendyk, R. W., & Augustine, L. (2023) · Springer eBooks · doi:10.1007/978-3-030-86012-7_10 · Cited by 19
Špinka, M., Palečková, M., & Řeháková, M. (2015) · Behaviour · doi:10.1163/1568539x-00003327 · Cited by 19
Lahvis, G. P., Panksepp, J. B., Kennedy, B. C., Wilson, C. R., & Merriman, D. K. (2015) · Journal of comparative psychology · doi:10.1037/a0039435 · Cited by 20
Effects of cross-fostering on play and anxiety in juvenile Fischer 344 and Lewis rats
Siviy, S. M., Eck, S. R., McDowell, L. S., & Soroka, J. A. (2016) · Physiology & Behavior · doi:10.1016/j.physbeh.2016.11.035 · Cited by 17
Neale, D., Clackson, K., Georgieva, S., Dedetaş, H., Scarpate, M., Wass, S. V., & Leong, V. (2018) · Frontiers in Psychology · doi:10.3389/fpsyg.2018.00273 · Cited by 22
Perelberg, A., & Schuster, R. H. (2009) · Journal of comparative psychology · doi:10.1037/a0013585 · Cited by 19
Serotonin, motivation, and playfulness in the juvenile rat
Siviy, S. M., Deron, L. M., & Kasten, C. R. (2011) · Developmental Cognitive Neuroscience · doi:10.1016/j.dcn.2011.07.002 · Cited by 20
An Exploration of Play Behaviors in Raven Nestlings
Osvath, M., Osvath, H., & Bååth, R. (2014) · Animal Behavior and Cognition · doi:10.12966/abc.05.06.2014 · Cited by 19
The Significance of Ethological Studies: Playing and Peeing
Bekoff, M. (2014) · Springer eBooks · doi:10.1007/978-3-642-53994-7_3 · Cited by 22
Behavioral science, engineering, and poetry revisited.
Michel, G. F. (2010) · Journal of comparative psychology · doi:10.1037/a0017355 · Cited by 18
Natural Law Revisited: Wild Justice and Human Obligations for Other Animals
DEANE‐DRUMMOND, C. E. (2015) · Journal of the Society of Christian Ethics · doi:10.1353/sce.2015.0045 · Cited by 18
Pacheco, X. P. (2020) · Behavioral Ecology and Sociobiology · doi:10.1007/s00265-020-02880-7 · Cited by 20
Kmecová, N. G., Peťková, B., Kottferová, J., Skurková, L., & Mills, D. S. (2021) · Frontiers in Veterinary Science · doi:10.3389/fvets.2021.712310 · Cited by 18
Playing with Ideas The Affective Dynamics of Creative Play
Power, P. (2011) · American journal of play · Cited by 18
Do Birds of a Playful Feather Flock Together? Playfulness and Assortative Mating.
Chick, G., Proyer, R. T., Purrington, A., et al. (2020) · American journal of play · Cited by 18
Tiège, A. D., Verpooten, J., & Braeckman, J. (2021) · The Quarterly Review of Biology · doi:10.1086/713210 · Cited by 17
The keybox: Shape-frame fitting during tool use in Goffin’s cockatoos (Cacatua goffiniana)
Habl, C., & Auersperg, A. M. I. (2017) · PLoS ONE · doi:10.1371/journal.pone.0186859 · Cited by 18
The coevolution of juvenile play–fighting and adult competition
Cenni, C., & Fawcett, T. W. (2018) · Ethology · doi:10.1111/eth.12732 · Cited by 17
Reptiles in Space Missions: Results and Perspectives
Gulimova, V. I., Proshchina, A. E., Kharlamova, A. S., Krivova, Y. S., Barabanov, V., Berdiev, R. K., Асадчиков, В. Е., Buzmakov, A. V., Zolotov, D. A., & Saveliev, S. V. (2019) · International Journal of Molecular Sciences · doi:10.3390/ijms20123019 · Cited by 20
Birdsong and the Neural Regulation of Positive Emotion
Riters, L. V., Polzin, B. J., Maksimoski, A. N., Stevenson, S. A., & Alger, S. J. (2022) · Frontiers in Psychology · doi:10.3389/fpsyg.2022.903857 · Cited by 22
Environmental enrichment for reptiles in European zoos: Current status and perspectives
Bartolomé, A., Carazo, P., & Font, E. (2023) · Animal Welfare · doi:10.1017/awf.2023.43 · Cited by 16
Play-like behavior exhibited by the vinegar fly Drosophila melanogaster
Triphan, T., Ferreira, C. H., & Huetteroth, W. (2025) · Current Biology · doi:10.1016/j.cub.2025.01.025 · Cited by 19
The Socio-religious Brain: A Developmental Model
Finkel, D. N., Swartwout, P., & Sosis, R. H. (2010) · British Academy eBooks · doi:10.5871/bacad/9780197264522.003.0014 · Cited by 20
Compete to Play: Trade-Off with Social Contact in Long-Tailed Macaques (Macaca fascicularis)
Ballesta, S., Reymond, G., Pozzobon, M., et al. (2014) · PLoS ONE · doi:10.1371/journal.pone.0115965 · Cited by 17
Shimada, M. (2013) · Primates · doi:10.1007/s10329-013-0348-4 · Cited by 17
Development of social play in hamsters: Sex differences and their possible functions
Kyle, S. C., Burghardt, G. M., & Cooper, M. A. (2019) · Brain Research · doi:10.1016/j.brainres.2019.02.012 · Cited by 17
Self-citationAlison Gopnik, C., Frankenhuis, W. E., & Tomasello, M. (2020) · Philosophical Transactions of the Royal Society B Biological Sciences · doi:10.1098/rstb.2019.0489 · Cited by 17
The consistency of individual centrality across time and networks in wild vervet monkeys
Canteloup, C., Puga‐Gonzalez, I., Sueur, C., & van de Waal, E. (2021) · American Journal of Primatology · doi:10.1002/ajp.23232 · Cited by 23
The ontogeny of courtship behaviours in bat pups (Saccopteryx bilineata)
Strauss, M., Knörnschild, M., & von Helversen, O. (2010) · Behaviour · doi:10.1163/000579510x12632972494743 · Cited by 17
To play or not to play? That’s a resource abundance question
Auerbach, J., Kanarek, A. R., & Burghardt, G. M. (2015) · Adaptive Behavior · doi:10.1177/1059712315611188 · Cited by 17
Self-citationKuba, M. J., Gutnick, T., & Burghardt, G. M. (2014) · Cambridge University Press eBooks · doi:10.1017/cbo9781139058964.006 · Cited by 23
Self-citationPlay, aggressive conflict and reconciliation in pre-school children: what matters?
Cordoni, G., Demuru, E., Ceccarelli, E., et al. (2016) · Behaviour · doi:10.1163/1568539x-00003397 · Cited by 17
Adams, K. D., Rincon, A. M. R., Puyo, L. M. B., et al. (2017) · British Journal of Occupational Therapy · doi:10.1177/0308022616680363 · Cited by 17
Does behavioral flexibility contribute to successful play among juvenile rhesus macaques?
Yanagi, A., & Berman, C. M. (2017) · Behavioral Ecology and Sociobiology · doi:10.1007/s00265-017-2377-2 · Cited by 17
The dynamics of play – back to the basics of playing
Holst, J. (2017) · International Journal of Play · doi:10.1080/21594937.2017.1288383 · Cited by 17
Children’s holistic learning during self-initiated outdoor play in a Norwegian kindergarten
Aslanian, T. K., Bjerknes, A., & Andresen, A. K. (2023) · European Early Childhood Education Research Journal · doi:10.1080/1350293x.2023.2257911 · Cited by 16
Play vs exergaming: A conceptual analysis as to why exergaming is not play
Kosma, M. (2021) · Turkish Journal of Kinesiology · doi:10.31459/turkjkin.1015139 · Cited by 15
Play and welfare in domestic cats: Current knowledge and future directions
Henning, J. S. L., Fernandez, E. J., Nielsen, T., & Hazel, S. J. (2022) · Animal Welfare · doi:10.7120/09627286.31.4.005 · Cited by 15
Iki, S., & Hasegawa, T. (2019) · Animal Cognition · doi:10.1007/s10071-019-01325-7 · Cited by 15
Predictors of individual differences in play behavior in Eurasian lynx cubs
Антоневич, А. Л., Rödel, H. G., Hudson, R., et al. (2020) · Journal of Zoology · doi:10.1111/jzo.12761 · Cited by 16
Is the digitalization of play technological mutation or digital evolution?
Güneş, G. (2020) · Early Child Development and Care · doi:10.1080/03004430.2020.1787402 · Cited by 22
“The play behaviours of many animals in laboratory or natural environment have been recorded, and these data have been analysed with observational and descriptive methods over a long time (Bauer & Smuts, 2007; Burghardt, 2005; Dudink, Simonse, Marks, de Jonge, & Spruijt, 2006; Palagi, 2011).”
BackgroundMethodInfluentialCenni, C., Christie, J. B. A., der Pant, Y. V., et al. (2022) · Ethology · doi:10.1111/eth.13324 · Cited by 16
Need for speed: Sexual maturation precedes social maturation in gray mouse lemurs
Hohenbrink, S., Zimmermann, E., & Radespiel, U. (2015) · American Journal of Primatology · doi:10.1002/ajp.22440 · Cited by 16
Ethology, Interpersonal Neurobiology, and Play: Insights into the Evolutionary Origin of the Arts.
Dissanayake, E. (2017) · American journal of play · Cited by 16
The Origins, Evolution and Interconnections of Play and Ritual: Setting the Stage
Burghardt, G. M. (2017) · Cambridge University Press eBooks · doi:10.1017/9781316534663.003 · Cited by 17
Self-citationLooking at Dogs: Moving from Anthropocentrism to Canid Umwelt
Horowitz, A., & Hecht, J. (2014) · Springer eBooks · doi:10.1007/978-3-642-53994-7_9 · Cited by 16
Infant vocalization when alone: Possibility of early sound playing
Shimada, Y. M. (2012) · International Journal of Behavioral Development · doi:10.1177/0165025411431408 · Cited by 15
The exaptive potential of (object) play behavior
Leca, J., & Gunst, N. (2022) · International Journal of Play · doi:10.1080/21594937.2022.2152184 · Cited by 17
Play partner preferences among groups of unfamiliar juvenile male rats
Ham, J. R., & Pellis, S. M. (2024) · Scientific Reports · doi:10.1038/s41598-024-66988-w · Cited by 15
Palagi, E., & Cordoni, G. (2020) · Animals · doi:10.3390/ani10020241 · Cited by 15
New Directions in Studying the Evolution of Play
Burghardt, G. M., & Pellis, S. M. (2018) · Cambridge University Press eBooks · doi:10.1017/9781108131384.002 · Cited by 22
Self-citationGuiding Preschool Play for Cultural Learning: Preschool Design as Cultural Niche Construction
Samuelsson, R. (2020) · Frontiers in Psychology · doi:10.3389/fpsyg.2020.545846 · Cited by 23
Maroun, M., Sarussi-Elyahu, A., Yaseen, A., Hatoum, O. A., & Kritman, M. (2020) · Translational Psychiatry · doi:10.1038/s41398-020-01040-9 · Cited by 16
Understanding Dogs' Engagement with Interactive Games
Cox, E., Mancini, C., & Ruge, L. (2020) · International Conference on Animal-Computer Interaction (ACI) · doi:10.1145/3446002.3446122 · Cited by 15
Grimes, C., Brent, L. J. N., Weiss, M. N., Franks, D. W., Balcomb, K. C., Ellifrit, D. K., Ellis, S., & Croft, D. P. (2022) · Marine Mammal Science · doi:10.1111/mms.12908 · Cited by 15
Brejcha, J., & Kleisner, K. (2015) · Biosemiotics · doi:10.1007/s12304-015-9249-9 · Cited by 15
The Janus-Faced Nature of Comparative Psychology – Strength or Weakness?
Burghardt, G. M. (2013) · Evolutionary Psychology · doi:10.1177/147470491301100317 · Cited by 14
Self-citationAdult playful individuals have more long- and short-term relationships
Moraes, Y. L., Varella, M. A. C., da Silva, C. S. A., & Valentová, J. V. (2021) · Evolutionary Human Sciences · doi:10.1017/ehs.2021.19 · Cited by 14
Playing geopolitics: utopian simulations and subversions of international relations
Dittmer, J. (2015) · GeoJournal · doi:10.1007/s10708-015-9655-1 · Cited by 15
McDonald, P. D. (2014) · Games and Culture · doi:10.1177/1555412014549192 · Cited by 14
Lu, P., & van Ameijde, J. (2025) · Cities & Health · doi:10.1080/23748834.2024.2441554 · Cited by 15
Dances with dogs: interspecies play and a case for sympoietic enactivism
Merritt, M. (2021) · Animal Cognition · doi:10.1007/s10071-020-01468-y · Cited by 14
Cordoni, G., Ciarcelluti, G., Pasqualotto, A., Perri, A., Bissiato, V., & Norscia, I. (2023) · American Journal of Primatology · doi:10.1002/ajp.23537 · Cited by 16
Unexpected behavior in the Cretaceous: tooth-marked bones attributable to tyrannosaur play
Rothschild, B. M. (2014) · Ethology Ecology & Evolution · doi:10.1080/03949370.2014.928655 · Cited by 14
O’Meara, B. C., Graham, K. L., Pellis, S. M., et al. (2015) · Adaptive Behavior · doi:10.1177/1059712315611733 · Cited by 14
Self-citation
Metadata
- Authors
- Burghardt, G. M.
- Corresponding author
- Burghardt, Gordon M.
- ORCID
- Burghardt, Gordon M.
- Venue
- The MIT Press eBooks
- Publisher
- The MIT Press
- Published
- 2005-02-04
- OpenAlex
- W4235808493
- Cited by
- 1,094
- References
- 28
- Citations by year
- 2026: 47 · 2025: 80 · 2024: 53 · 2023: 73 · 2022: 71 · 2021: 59 · 2020: 60 · 2019: 97 · 2018: 84 · 2017: 64 · 2016: 51 · 2015: 61 · 2014: 64 · 2013: 39 · 2012: 36
- FWCI
- 19.86
- Type
- book
- Language
- en
- Open access
- hybrid
- doi.org
- Licence
- Locations
- The MIT Press eBooks (publishedVersion, cc-by-nc-nd)
- Topics
- Life Sciences › Agricultural and Biological Sciences › Ecology, Evolution, Behavior and Systematics › Primate Behavior and Ecology
- Life Sciences › Agricultural and Biological Sciences › Ecology, Evolution, Behavior and Systematics › Animal Behavior and Reproduction
- Social Sciences › Psychology › Developmental and Educational Psychology › Child and Animal Learning Development
- Keywords
- animal play, evolution of play, playfulness, placental mammals, human development, comparative ethology
About these checks
Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.
Statistics and arithmetic are recomputed, not judged.
Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.
What counts as a claim ›How we measure confidence ›How we check this ›
Are you an author, or do you see a problem with this page? Request a review