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	<front>
		<journal-meta>
			<journal-id journal-id-type="publisher-id">pusp</journal-id>
			<journal-title-group>
				<journal-title>Psicologia USP</journal-title>
				<abbrev-journal-title abbrev-type="publisher">Psicol. USP</abbrev-journal-title>
			</journal-title-group>
			<issn pub-type="ppub">0103-6564</issn>
			<issn pub-type="epub">1678-5177</issn>
			<publisher>
				<publisher-name>Instituto de Psicologia da Universidade de São Paulo</publisher-name>
			</publisher>
		</journal-meta>
		<article-meta>
			<article-id pub-id-type="doi">10.1590/0103-656420160122</article-id>
			<article-categories>
				<subj-group subj-group-type="heading">
					<subject>Artigos originais</subject>
				</subj-group>
			</article-categories>
			<title-group>
				<article-title>Brincar na perspectiva psicoetológica: implicações para pesquisa e prática</article-title>
				<trans-title-group xml:lang="fr">
					<trans-title>Approche psycho-éthologique du jeu: de la recherche à la pratique</trans-title>
				</trans-title-group>
				<trans-title-group xml:lang="es">
					<trans-title>El juego desde una perspectiva psicoetológica: implicaciones para la investigación y la práctica</trans-title>
				</trans-title-group>
			</title-group>
			<contrib-group>
				<contrib contrib-type="author">
					<name>
						<surname>Otta</surname>
						<given-names>Emma</given-names>
					</name>
					<xref ref-type="aff" rid="aff1"/>
					<xref ref-type="corresp" rid="c1"><sup>*</sup></xref>
				</contrib>
			</contrib-group>
			<aff id="aff1">
				<institution content-type="original">Universidade de São Paulo, Instituto de Psicologia, Departamento de Psicologia Experimental. São Paulo, SP, Brasil</institution>
				<institution content-type="normalized">Universidade de São Paulo</institution>
				<institution content-type="orgname">Universidade de São Paulo</institution>
				<institution content-type="orgdiv1">Instituto de Psicologia</institution>
				<institution content-type="orgdiv2">Departamento de Psicologia Experimental</institution>
				<addr-line>
					<city>São Paulo</city>
					<state>SP</state>
				</addr-line>
				<country country="BR">Brazil</country>
			</aff>
			<author-notes>
				<corresp id="c1">
					<label>*</label>Endereço para correspondência: <email>emmaotta@usp.br</email>
				</corresp>
			</author-notes>
			<pub-date pub-type="epub-ppub">
				<season>Sep-Dec</season>
				<year>2017</year>
			</pub-date>
			<volume>28</volume>
			<issue>3</issue>
			<fpage>358</fpage>
			<lpage>367</lpage>
			<history>
				<date date-type="received">
					<day>22</day>
					<month>08</month>
					<year>2016</year>
				</date>
				<date date-type="rev-recd">
					<day>26</day>
					<month>01</month>
					<year>2017</year>
				</date>
				<date date-type="accepted">
					<day>11</day>
					<month>05</month>
					<year>2017</year>
				</date>
			</history>
			<permissions>
				<license license-type="open-access" xlink:href="https://creativecommons.org/licenses/by-nc-nd/4.0/" xml:lang="pt">
					<license-p>Este é um artigo publicado em acesso aberto sob uma licença Creative Commons</license-p>
				</license>
			</permissions>
			<abstract>
				<title>Resumo</title>
				<p>Este ensaio trata do brincar a partir da perspectiva psicoetológica e examina implicações para a pesquisa e a prática. Ao longo das últimas décadas, crianças vêm ganhando oportunidades de escolarização e atividades dirigidas por adultos, mas perdendo oportunidades de brincadeira livre autogerenciada. Isto é preocupante, considerando as indicações de modelos animais de que a brincadeira social autogerenciada é importante para o desenvolvimento do cérebro social e da capacidade de autorregulação de emoções. Este estudo representa um convite-justificativa para que as crianças recuperem oportunidades de brincadeira natural das quais vêm sendo privadas. Quanto mais conhecermos sobre o brincar, mais adequados seremos nas oportunidades que poderemos oferecer a elas. Precisamos de mais pesquisa sobre este tema na academia, num ambiente intelectual que facilite a colaboração entre etólogos, psicólogos, educadores e neurocientistas, promovendo interação bidirecional entre teoria e prática.</p>
			</abstract>
			<trans-abstract xml:lang="fr">
				<title>Résumé</title>
				<p>Cet article se concentre sur le jeu dans la perspective psycho-éthologique et examine les implications pour la recherche et la pratique. Au cours des dernières décennies, les enfants reçoivent plus de possibilités d‘éducation et activités dirigées par des adultes, mais souffrent d‘un grave déficit de jeu autogéré. Cette situation est particulièrement préoccupante compte tenu des indications de modèles animaux que le jeu social autogéré est très important pour le développement du cerveau social et d‘autorégulation émotionnelle. Ce texte est une invitation/justification pour promouvoir des occasions de jeu naturel pour les enfants. Plus on connaît les fondamentaux de jeu, le plus approprié seront les opportunités que nous pouvons offrir à nos enfants. Nous avons besoin de toute urgence davantage de recherches sur ce sujet, dans un environnement intellectuel qui facilitent les collaborations entre les éthologues, les psychologues, les éducateurs et les neuroscientifiques, et la promotion d‘une interaction bidirectionnelle entre la théorie et la pratique.</p>
			</trans-abstract>
			<trans-abstract xml:lang="es">
				<title>Resumen</title>
				<p>Este ensayo trata del juego desde el punto de vista psicoetológico y examina implicaciones para la investigación y la práctica. A lo largo de las últimas décadas, los niños han recibido oportunidades de escolarización y actividades dirigidas por adultos, pero han perdido oportunidades para el juego libre y autogestionado. Lo que resulta preocupante, teniendo en cuenta las sugerencias de los modelos animales de que el juego social autogestionado es importante para el desarrollo del cerebro social y de la capacidad de autorregulación emocional. Este artículo es una invitación/justificación para que los niños recuperen oportunidades para el juego natural del que han sido privados. Cuánto más sepamos acerca del juego, más éxito tendremos. Necesitamos más investigación sobre este tema en la academia, en un ambiente intelectual que facilite la colaboración entre los etólogos, psicólogos, educadores y neurocientíficos, para promover una interacción bidireccional entre la teoría y la práctica.</p>
			</trans-abstract>
			<kwd-group xml:lang="pt">
				<title>Palavras-chave:</title>
				<kwd>brincar</kwd>
				<kwd>cérebro social</kwd>
				<kwd>desenvolvimento</kwd>
				<kwd>emoções</kwd>
				<kwd>natureza</kwd>
			</kwd-group>
			<kwd-group xml:lang="fr">
				<title>Mots-clés:</title>
				<kwd>jouer</kwd>
				<kwd>cerveau social</kwd>
				<kwd>développement</kwd>
				<kwd>émotion</kwd>
				<kwd>nature</kwd>
			</kwd-group>
			<kwd-group xml:lang="es">
				<title>Palabras clave:</title>
				<kwd>juego</kwd>
				<kwd>cerebro social</kwd>
				<kwd>desarrollo</kwd>
				<kwd>emociones</kwd>
				<kwd>naturaleza</kwd>
			</kwd-group>
			<counts>
				<fig-count count="2"/>
				<table-count count="2"/>
				<equation-count count="0"/>
				<ref-count count="92"/>
				<page-count count="10"/>
			</counts>
		</article-meta>
	</front>
	<body>
		<sec sec-type="intro">
			<title>Introdução</title>
			<p>Este ensaio trata do brincar a partir da perspectiva psicoetológica e examina as implicações desta abordagem para pesquisa e prática relativas a um tema que considero negligenciado na área acadêmica. O termo “abordagem psicoetológica” foi cunhado por Walter Hugo de Andrade <xref ref-type="bibr" rid="B29">Cunha, pioneiro da etologia no Brasil (Cunha, 1965</xref>, <xref ref-type="bibr" rid="B30">2004</xref>) e difundido pelos que seguiram sua proposta inspiradora (<xref ref-type="bibr" rid="B7">Arcieri, 1995</xref>; <xref ref-type="bibr" rid="B8">Ardans, 1996</xref>; <xref ref-type="bibr" rid="B3">Ades, 1998</xref>; <xref ref-type="bibr" rid="B47">Lencastre, 2010</xref>; <xref ref-type="bibr" rid="B49">Lucena &amp; Pedrosa, 2014</xref>). Lencastre (2010) destaca que a psicoetologia consiste na busca de conciliação do estudo biológico do comportamento com a atividade psicológica. Ades (1986, 1987) via a psicoetologia como abordagem integrada aos processos comportamentais básicos, aproximando a etologia (e a ecologia comportamental) da psicologia experimental, que se desenvolveram historicamente por caminhos apartados, tendo essa abordagem os seguintes pontos programáticos: escolha de comportamentos ecologicamente relevantes (sistemas funcionais) como foco inicial de análise; aprendizagem como fenômeno adaptativo a ocorrer dentro de sistemas funcionais; estudo das diferenças interespecíficas dentro de um quadro ecológico de referência; e papel complementar de estudos de campo e de laboratório numa heurística recíproca. Fundamentada nesta abordagem, concordando com <xref ref-type="bibr" rid="B1">Ades (1986</xref>, <xref ref-type="bibr" rid="B2">1987</xref>) sobre suas vantagens enquanto geradora de pesquisa e fonte de subsídios para uma teoria geral do comportamento animal, e inspirada no manifesto da etologia brasileira (Cunha, 1965), apresento um convite-justificativa para o estudo do comportamento de brincar.</p>
		</sec>
		<sec>
			<title>A razão da etóloga, fascinada pela observação do comportamento</title>
			<p>Por que convidar a estudar o comportamento de brincar dos animais? A resposta mais simples que poderia dar é o fascínio pela observação do comportamento espontâneo, livre de limites artificiais. É divertido observar e pensar sobre o comportamento. É instigante ler relatos de observações naturalísticas que muitas vezes prosseguem durante vários anos. Escolhi dois exemplos para convidar os leitores a pensar no assunto com base em relatos de observações feitas por etólogos: brincadeira de galho e brincadeira com pedregulhos.</p>
			<p>O primeiro exemplo foi extraído de um artigo de <xref ref-type="bibr" rid="B43">Kahlenberg e Wrangham (2010</xref>), tomando como ponto de partida a questão: “<italic>chimpanzés usam galhos como se fossem bonecas?</italic>”. Neste estudo, ao longo de catorze anos de observação do comportamento de chimpanzés no Parque Nacional de Kibale, em Uganda, foram reunidos mais de cem episódios de carregar galhos como se fossem “bonecas”. É interessante notar que este comportamento não foi observado em outras comunidades, levantando a possibilidade que os chimpanzés estejam copiando uma tradição comportamental local. Alguns episódios eram breves e duravam apenas alguns minutos, mas outros eram longos, chegavam a durar mais de uma hora. Os pedaços de galhos escolhidos para carregar eram diferentes - maiores e mais largos - que os pedaços estreitos e finos usados como instrumentos, em contexto de forrageamento, na pescaria de térmitas. Observações qualitativas a ser apresentadas: alguns juvenis carregavam galhos para o ninho e dormiam com eles e, numa ocasião, foi observada construção de um ninho separado para o galho. Kakama (8 anos), deslocando-se com sua mãe grávida, pegou um pedaço de galho e o carregou por horas, tratando-o como se fosse um bebê (fez um ninho e colocou o galho nele). Quatro meses depois, dois assistentes de pesquisa, que não conheciam o incidente, observaram comportamento semelhante do mesmo indivíduo, que coletou outro pedaço de galho, que foi chamado de o “<italic>bebê de brinquedo de Kakama</italic>”. Em outra oportunidade, a chimpanzé foi observada carregando um galho, inclusive batendo nele como se estivesse “<italic>batendo nas costas de um bebê</italic>”, enquanto sua mãe carregava seu irmão doente. Os pesquisadores observaram também filhotes brincando de uma versão de “avião”, deitados de costas com seu galho, balançando-o com os braços levantados. Mães fazem esta brincadeira com filhotes.</p>
			<p>O segundo exemplo foi extraído de um conjunto de artigos de Michael <xref ref-type="bibr" rid="B41">Huffman (Huffman, 1984</xref>; <xref ref-type="bibr" rid="B42">Huffman &amp; Quiatt, 1986</xref>; <xref ref-type="bibr" rid="B53">Nahallage &amp; Huffman, 2007</xref>, <xref ref-type="bibr" rid="B54">2012</xref>) sobre brincadeira com pedregulhos em quatro grupos de <italic>Macaca fuscata</italic> em cativeiro e em onze grupos provisionados em vida livre. Essa forma de brincadeira consiste em manipulação repetitiva de pedregulhos: espalhar e reunir, rolar de uma mão para outra, bater um pedregulho no outro produzindo som, bater contra o substrato, esfregar, jogar, colocar na água, lavar na água, envolver com folhas, catar outro indivíduo com pedregulho, correr e atirar. Alguns episódios eram breves (menos de um minuto), mas outros eram longos (vinte minutos). O comportamento foi observado pela primeira vez em Arashiyama, Japão, como inovação de uma fêmea juvenil, que então se espalhou para outros jovens e filhotes do grupo. A difusão do comportamento foi observada ao longo de 25 anos, à medida que os indivíduos se tornaram adultos e tiveram seus próprios filhotes.</p>
			<p>Estes são apenas dois exemplos para introduzir o assunto e convidar os leitores a refletir sobre o comportamento de brincar dos animais, sobre porque estudá-lo e sobre o possível valor de uma abordagem comparativa.</p>
		</sec>
		<sec>
			<title>Ciência “Dura” versus Ciência “Leve”: Desqualificação do brincar como um tema de pesquisa pelo homem “sério”</title>
			<p>Embora etólogos estudem o brincar e suas conclusões sejam sistematizadas em vários livros (<xref ref-type="bibr" rid="B11">Bateson &amp; Martin, 2013</xref>; <xref ref-type="bibr" rid="B15">Bekoff &amp; Byers, 1998</xref>; <xref ref-type="bibr" rid="B25">Burghardt, 2005</xref>; <xref ref-type="bibr" rid="B71">Pellegrini &amp; Smith, 2005</xref>) e artigos de revisão (<xref ref-type="bibr" rid="B26">Burghardt, 2010</xref>; <xref ref-type="bibr" rid="B37">Graham &amp; Burghardt, 2010</xref>), comparativamente constata-se negligência deste tema de estudo em relação a outros em obras de referência na área. Apesar da universalidade do brincar nos animais e no homem, observada em crianças em diferentes culturas (<xref ref-type="bibr" rid="B36">Gosso, Otta, Morais, Ribeiro &amp; Bussab, 2005</xref>; <xref ref-type="bibr" rid="B50">Meirelles, 2007</xref>), há quem considere o ato como atividade frívola e até prejudicial. Uma revisão dessas representações pode ser encontrada em Burghardt (2005), que, em seu livro, cita como exemplo de interpretações negativas do brincar a perda de tempo, que pode ter como consequência negligenciar estudo e trabalho e até levar à delinquência, ao jogo e ao crime.</p>
			<p>Em relação ao comportamento animal, constata-se que livros-texto como o clássico <italic>Animal Behavior</italic> de John <xref ref-type="bibr" rid="B6">Alcock (2013</xref>), que se encontra em sua décima edição, não incluem capítulos sobre brincadeira, embora discorram sobre desenvolvimento. Uma razão para a relativa negligência da brincadeira na academia é a aparente falta de seriedade do comportamento, nas suas manifestações proximais ou na sua função. Talvez os cientistas, incluindo etólogos, psicólogos evolucionistas e neurocientistas, vejam a brincadeira como assunto não sério e, portanto, não importante para estudo.</p>
			<p>O renomado neurocientista Jaak Panksepp, que cunhou o termo “neurociência afetiva” em 1992, comenta a reação da audiência a uma apresentação do seu trabalho sobre brincadeira em ratos e vocalizações ultrassônicas exibidas em contexto lúdico (<xref ref-type="bibr" rid="B69">Panksepp, Siviy, &amp; Normansell, 1985</xref>; <xref ref-type="bibr" rid="B67">Panksepp &amp; Burgdorf, 2003</xref>; Panksepp, 2007b):</p>
			<disp-quote>
				<p>Quando apresentei pela primeira vez nosso trabalho sobre “riso” em ratos . . . num simpósio do National Institute of Mental Health (NIMH) em 1998, . . . não houve uma única pergunta de uma gélida audiência de neurobehavioristas. Um dos organizadores do evento me puxou para um lado depois da minha sessão e, em síntese, disse “Essa pesquisa é maravilhosa. Poderia fornecer um modelo simplificado para emoções positivas, assim como o condicionamento clássico de imobilização e intensificação de sobressalto é usado para estudar medo… mas, por favor, não chame de riso.” Repliquei, “Sim, eu poderia fazer isto, mas então estaria mentindo, porque acredito que esta resposta pode ser a fonte ancestral do riso infantil.” É uma pena quando cientistas dedicados são desencorajados a considerar as dimensões afetivas de funções cerebrais no seu estudo do comportamento animal e são fortemente encorajados a restringir suas discussões a mera descrições comportamentais e terminologias da teoria de aprendizagem. (<xref ref-type="bibr" rid="B61">Panksepp, 2005</xref>, p. 67)</p>
			</disp-quote>
			<p>Entrei em contato em 1998, e passei a rever e acompanhar deste então (por exemplo, <xref ref-type="bibr" rid="B59">Panksepp, 1992</xref>, 1998; <xref ref-type="bibr" rid="B66">Panksepp &amp; Biven, 2012</xref>) o trabalho de Jaak Panksepp, professor emérito do Departamento de Psicologia da Bowling Green State University e da Washington State University. Li com muito interesse o livro <italic>Affective Neuroscience: The Foundations of Human and Animal Emotions</italic>, que usamos na disciplina Motivação e Emoção, que ministrei durante mais de trinta anos em conjunto com César Ades no curso de graduação em Psicologia do Instituto de Psicologia da Universidade de São Paulo, na medida em que vem ao encontro da abordagem psicoetológica que nos norteia. Lembro-me das conversas com César (<xref ref-type="bibr" rid="B55">Otta, 2012</xref>, <xref ref-type="bibr" rid="B56">2015</xref>) sobre as pesquisas mostrando que ratos “dão risada” - emitem vocalizações ultrassônicas de 50 kHz, rápidas (&lt;0,3 s), que o ouvido humano não é capaz de identificar, mas que podem ser registradas por meio de equipamentos e submetidas à análise sonográfica - em circunstâncias afetivas positivas como brincadeira (<xref ref-type="bibr" rid="B21">Burgdorf &amp; Panksepp, 2001</xref>; <xref ref-type="bibr" rid="B24">Burgdorf; Burgdorf, Kroes, Moskal, Pfaus, Brudzynski, &amp; Panksepp, 2008</xref>; <xref ref-type="bibr" rid="B44">Knutson, Burgdorf, &amp; Panksepp, 1998</xref>; <xref ref-type="bibr" rid="B20">Brudzynski &amp; Pniak, 2002</xref>), acasalamento (Burgdorf et al., 2008), em resposta a drogas de abuso, como anfetamina (<xref ref-type="bibr" rid="B23">Burgdorf, Knutson, Panksepp, &amp; Ikemoto, 2001</xref>; <xref ref-type="bibr" rid="B83">Thompson, Leonard, &amp; Brudzynski, 2006</xref>) e antecipação de recompensas (<xref ref-type="bibr" rid="B22">Burgdorf, Knutson, &amp; Panksepp, 2000</xref>). E também choramingam - emitem vocalizações ultrassônicas de 22 kHz, longas (&gt;0,3 s), - em circunstâncias afetivas negativas, como encontro com um predador (<xref ref-type="bibr" rid="B17">Blanchard, Blanchard, Agullana, &amp; Weiss, 1991</xref>), derrota por um conspecífico (<xref ref-type="bibr" rid="B82">Thomas, Takahashi, &amp; Barfield, 1983</xref>), durante a retirada de drogas como álcool, benzodiazepínicos, opiáceos e psicoestimulantes (<xref ref-type="bibr" rid="B28">Covington &amp; Miczek, 2003</xref>; <xref ref-type="bibr" rid="B88">Vivian et al., 1994</xref>) e antecipação de estimulação aversiva (<xref ref-type="bibr" rid="B27">Choi &amp; Brown, 2003</xref>; <xref ref-type="bibr" rid="B45">Lee, Choi, Brown, &amp; Kim, 2001</xref>). As vocalizações ultrassônicas de 50 kHz expressam estado positivo, apetitivo e servem como sinais sociais afiliativos, enquanto as vocalizações ultrasônicas de 22 kHz expressam estado negativo, aversivo, e servem como sinal de alarme. Tendo a possibilidade, ratos se autoadministram playback de vocalizações de 50 kHz e evitam playback de vocalizações de 22 kHz (Burgdorf et al., 2008). <xref ref-type="bibr" rid="B70">Parsana e Brown (2012</xref>) mostraram que vocalizações ultrassônicas de 22 kHz e 50 kHz estão associadas a respostas comportamentais opostas e à ativação ou desativação da amígdala.</p>
		</sec>
		<sec>
			<title>Brincar como um tema de pesquisa à luz dos porquês da etologia: adição de um quinto nível de análise</title>
			<p>Lembro que, além de ser um etólogo renomado, César Ades gostava de brincar. No Centro de Memória do IPUSP, hoje Museu de Psicologia, guardamos várias fotografias do professor (<xref ref-type="fig" rid="f1">Figura 1</xref>), que trazia seu espírito lúdico para a sala de aula e para todas as suas atividades. Exploração e brincadeira foram temas de suas aulas e pesquisas (<xref ref-type="bibr" rid="B4">Ades, 2000</xref>, <xref ref-type="bibr" rid="B5">2012</xref>; <xref ref-type="bibr" rid="B33">Gomide &amp; Ades, 1989</xref>). Nas fotografias a seguir, Ades aparece dando uma entrevista no seu escritório, num congresso científico, e também, numa semana de calouros dos alunos do curso de graduação em psicologia da USP, com o boneco símbolo da Atlética e durante uma corrida de saco.</p>
			<p>
				<fig id="f1">
					<label>Figura 1</label>
					<caption>
						<title>Lembranças de César Ades, professor, pesquisador e parceiro de brincadeira</title>
					</caption>
					<graphic xlink:href="1678-5177-pusp-28-03-358-gf1.jpg"/>
					<attrib>Fonte: Museu de Psicologia do Instituto de Psicologia da Universidade de São Paulo.</attrib>
				</fig>
			</p>
			<p>Tendo o modelo de César, foi com surpresa que entrei em contato com a recomendação “<italic>Não sorria até o Natal!</italic>” (<xref ref-type="bibr" rid="B76">Ryan, 1972</xref>). Professores deveriam começar o ano letivo com expressão grave e pouco convidativa à interação próxima, com o objetivo de manter a disciplina em sala de aula. Com César aprendi que, ao contrário, é possível sorrir e rir em sala de aula e também aprendi que brincar é tema digno de investigação na academia. Penso que incentivou também alguns dos meus colegas que estudaram a brincadeira de macacos-prego (<xref ref-type="bibr" rid="B74">Resende &amp; Ottoni, 2002</xref>), de golfinhos (<xref ref-type="bibr" rid="B80">Spinelli, Nascimento, &amp; Yamamoto, 2002</xref>), de ratos e hamsters (<xref ref-type="bibr" rid="B86">Vieira &amp; Sartorio, 2002</xref>) e de biguás e socozinhos (<xref ref-type="bibr" rid="B77">Sazima, 2008</xref>). No entanto, ainda há poucos estudos de comportamento animal sobre brincadeira no Brasil, que não é tópico usual em cursos de comportamento animal nem em congressos da área. Trata-se de um tema a ser (re)descoberto!</p>
			<p>Em pesquisa realizada com Paula Gomide, César mostrou que atividades tenderão a ser percebidas com maior probabilidade como brincadeira do que como trabalho se crianças se engajarem voluntariamente. Se pré-escolares receberem recompensas por brincar com brinquedos no <italic>playground</italic>, passarão menos tempo engajadas nestas atividades do que se a única motivação for o prazer intrínseco da atividade (Gomide &amp; Ades, 1989). Paradoxalmente, a disposição para brincar é reduzida por recompensas externas, se a criança escolher livremente, seu engajamento com a atividade aumenta, especialmente se a sua habilidade numa tarefa desafiadora melhorar com a prática (<xref ref-type="bibr" rid="B10">Bateson, 2005</xref>; <xref ref-type="bibr" rid="B31">Deci &amp; Ryan, 1980</xref>).</p>
			<p>Segundo <xref ref-type="bibr" rid="B81">Spinka, Newberry e Bekoff (2001</xref>), o comportamento lúdico permite aos animais desenvolverem respostas motoras e emocionais a eventos inesperados em que experimentam perda repentina de controle, tornando-se mais versáteis. Para obter “<italic>treino para o inesperado</italic>”, sugerem que os animais buscam ativamente e criam situações inesperadas na brincadeira por meio <italic>de autoincapacitação</italic>;<xref ref-type="fn" rid="fn1"><sup>1</sup></xref> isto é, colocam-se ativamente em posições e situações desvantajosas. A brincadeira é formada por sequências em que os envolvidos alternam rapidamente entre movimentos bem controlados, como os usados no comportamento “sério”, e movimentos que resultam na perda temporária de controle. Esta alternância entre ter controle e perdê-lo, que caracteriza a <italic>autoincapacitação</italic>, gera demandas cognitivas e estado emocional complexo chamado por Spinka, Newberry e Bekoff (2001) de “divertir-se”.<xref ref-type="fn" rid="fn2"><sup>2</sup></xref> Evidentemente esta é uma inferência de estado emocional indicada pelo uso de aspas. Os leitores interessados podem encontrar discussão sobre inferências de estados afetivos a partir de observações comportamentais que incluem propostas de substituição de antroponegação por antropomorfismo crítico (<xref ref-type="bibr" rid="B14">Bekoff, 2006</xref>; <xref ref-type="bibr" rid="B25">Burghardt, 2005</xref>; <xref ref-type="bibr" rid="B89">Waal, 1997</xref>, <xref ref-type="bibr" rid="B90">1999</xref>, <xref ref-type="bibr" rid="B91">2011</xref>; <xref ref-type="bibr" rid="B65">Panksepp, 2011</xref>).</p>
			<p>Os porquês da Etologia podem ser formulados em relação ao brincar norteando a pesquisa, com a proposta mais recente de adição de um quinto nível de análise (Burghard, 2005), além dos quatro porquês originalmente formulados por <xref ref-type="bibr" rid="B84">Tinbergen (1963</xref>): <italic>causa</italic> (quais são os processos internos e externos que levam ao desempenho de comportamento lúdico?); <italic>ontogênese</italic> (como o brincar se desenvolve durante a vida do indivíduo?); <italic>função adaptativa</italic> (quais são as consequências da brincadeira para um animal?); e <italic>filogênese</italic> (como a brincadeira evoluiu da não brincadeira e qual foi sua história evolutiva?). Um quinto nível de análise (<xref ref-type="table" rid="t1">Tabela 1</xref>) foi acrescentado por Burghard (2005):</p>
			<disp-quote>
				<p>Tinbergen deixou de lado um grupo de fenômenos dos seus quatro porquês: os aspectos emocionais, vivenciais ou fenomenológicos do comportamento. Ele fez isto em virtude . . . do Zeitgeist behaviorista na psicologia acadêmica americana e européia . . . A negação de fatores subjetivos não teve um efeito negativo sobre a maior parte da pesquisa etológica e provavelmente foi salutar: havia tanta pesquisa básica a ser feita. No que diz respeito à descrição e análise da diversidade de padrões comportamentais envolvidos no cortejamento, predação e organização social. Uma consequência, contudo, foi assegurar que o brincar continuasse sendo um assunto em larga medida negligenciado por pesquisadores que queriam ser considerados cientistas “duros” em vez de cientistas “leves”. A fim de corrigir a omissão da “experiência privada” no estudo do comportamento, acrescentei um quinto porquê para complementar os quatro porquês de Tinbergen . . . . Não vou repetir aqui as razões para isso, mas novos métodos, incluindo imageamento cerebral, neuroendocrinologia, neuroquímica e farmacologia . . . tem levado a uma maior necessidade de incorporar estas questões na etologia e na psicologia. (pp. 13-14)</p>
			</disp-quote>
			<p>
				<table-wrap id="t1">
					<label>Tabela 1</label>
					<caption>
						<title>Cinco níveis de análise da etologia aplicados ao brincar</title>
					</caption>
					<table>
						<colgroup>
							<col/>
							<col/>
						</colgroup>
						<thead>
							<tr>
								<th align="center">Nível de análise</th>
								<th align="center">Descrição</th>
							</tr>
						</thead>
						<tbody>
							<tr>
								<td align="center">Causa</td>
								<td align="center">Fatores internos e externos subjacentes ao comportamento</td>
							</tr>
							<tr>
								<td align="center">Ontogênese</td>
								<td align="center">Padrões e processos de mudança do comportamento ao longo do desenvolvimento</td>
							</tr>
							<tr>
								<td align="center">Função adaptativa</td>
								<td align="center">Contribuição do comportamento para a sobrevivência do indivíduo, do grupo, para a reprodução, aptidão inclusiva</td>
							</tr>
							<tr>
								<td align="center">Filogênese</td>
								<td align="center">Padrões históricos de mudança comportamental entre gerações e taxa</td>
							</tr>
							<tr>
								<td align="center">Experiência privada</td>
								<td align="center">Experiência subjetiva. Heterofenomenologia.</td>
							</tr>
						</tbody>
					</table>
					<table-wrap-foot>
						<fn id="TFN1">
							<p>Fonte: Adaptado de <xref ref-type="bibr" rid="B25">Burghardt, 2005</xref>
							</p>
						</fn>
					</table-wrap-foot>
				</table-wrap>
			</p>
			<p>
				<xref ref-type="bibr" rid="B25">Burghardt (2005</xref>) propõe cinco critérios para caracterizar o brincar: <italic>funcionalidade incompleta</italic> - o comportamento não é completamente funcional na forma ou no contexto em que se expressa, incluindo elementos que não contribuem para a sobrevivência atual (de fato é difícil visualizar funcionalidade quando se observa um indivíduo de <italic>Macaca fuscata</italic> que gasta vinte minutos espalhando e juntando pedregulhos) (<xref ref-type="bibr" rid="B41">Huffman, 1984</xref>); <italic>estado motivacional</italic> - o comportamento é espontâneo, voluntário, prazeroso, recompensador por si mesmo e autotélico; <italic>o brincar difere das expressões estritamente funcionais de comportamento</italic> - é estruturalmente ou temporalmente diferente dos comportamentos sérios relacionados: incompleto (com os elementos finais inibidos ou ausentes), exagerado, desajeitado, precoce. Ou seja, envolve comportamentos modificados quanto à forma, à sequência ou ao alvo, considerando-se suas contrapartidas sérias; <italic>o comportamento é repetido</italic> - é realizado repetidamente, de forma semelhante, mas não rigidamente estereotipado, durante pelo menos parte do período de vida do animal; e <italic>campo motivacional</italic> - o comportamento é iniciado quando o animal está num “campo relaxado”, por exemplo, quando não está sob estresse de perigo físico, doença, condições meteorológicas adversas, instabilidade social ou sistemas competitivos intensos (como medo).</p>
			<p>Há evidências de que risco de predação indicado por cheiro de gato suprime brincadeira em filhotes de ratos (<xref ref-type="bibr" rid="B40">Hubbard, Blanchard, Yang, Markham, Gervacio, Chun-I, &amp; Blanchard, 2004</xref>; <xref ref-type="bibr" rid="B79">Siviy, Harrison, &amp; McGregor, 2006</xref>). <xref ref-type="bibr" rid="B60">Panksepp (1998</xref>) mostrou que a supressão era específica, sendo encontrada quando colocou pelos de gato no espaço onde os filhotes brincavam, mas não quando colocou pelos de cachorro. <xref ref-type="bibr" rid="B78">Siviy (2010</xref>) conclui que a brincadeira parece ser resiliente face à adversidade nos filhotes de ratos. É como se o cérebro tivesse evoluído para ver uma vantagem adaptativa em parar de brincar diante do risco de predação, mas, passado o risco, os filhotes voltam a brincar, como se o cérebro não visse razão adaptativa em continuar a manter sentimentos de medo e ansiedade. Contudo, podemos nos equivocar em relação ao que é uma ameaça e prever supressão de brincadeira quando não ocorre. É o que evidencia Stuart <xref ref-type="bibr" rid="B19">Brown (2009</xref>) com uma sequência notável de fotos de brincadeira entre um urso e um cão, numa época de escassez de alimento. Em vez de tornar-se presa, o cão, muito menor do que o urso, revelou-se parceiro de uma longa e aparentemente relaxada brincadeira. Predominou um “<italic>estado de espírito lúdico</italic>” em vez de um “<italic>estado de espírito sério</italic>”. O urso se comportou de acordo os princípios descritos por Mark <xref ref-type="bibr" rid="B16">Bekoff e Jessika Pierce (2010</xref>) no seu artigo intitulado “O cão ético”, levou em conta a capacidade do seu parceiro, criando e mantendo uma relação de igualdade, o que envolve: <italic>inversão de papéis -</italic> o animal dominante realiza uma ação durante a brincadeira que não ocorreria normalmente durante a agressão real e o animal mais fraco pode “atacar”; <italic>autocontenção</italic><xref ref-type="fn" rid="fn3"><sup>3</sup></xref><italic>-</italic> o animal mais forte não morde seu parceiro de brincadeira tão fortemente quanto seria capaz, nem brinca tão vigorosamente quanto poderia; <italic>metacomunica</italic>ção - um animal parece reconhecer que seu parceiro está simulando e indica que ele próprio também está representando. Além de posturas, há uma cara de brincadeira que sinaliza que uma particular sequência é lúdica e não agressiva.</p>
			<p>Observações comparativas interessantes foram feitas por <xref ref-type="bibr" rid="B58">Palagi e Cordoni (2012</xref>), mostrando que a brincadeira social de bonobos (<italic>Pan paniscus</italic>) e de chimpanzés comuns (<italic>Pan troglodytes</italic>) é semelhante quando são filhotes. No entanto, no período juvenil, a brincadeira dos bonobos transforma-se com menor frequência em agressão, dura mais e pode envolver mais de dois parceiros simultaneamente. Quando adultos, os bonobos continuam brincando, mas os chimpanzés comuns não, o que provavelmente se deve à diferença em tolerância social das duas espécies (<xref ref-type="bibr" rid="B57">Palagi, 2006</xref>; Palagi &amp; Cordoni, 2012).</p>
		</sec>
		<sec>
			<title>PEXE OXEMOARAI: convite-justificativa para reavaliarmos nossas prioridades</title>
			<p>Convido-os agora a pensar sobre a nossa própria espécie, a partir do contexto de perspectiva psicoetológica apresentado acima. Partilho o ponto de vista de Peter <xref ref-type="bibr" rid="B38">Gray (2011</xref>a) de que as crianças humanas foram desenhadas pela seleção natural para adquirir a cultura por meio da brincadeira e exploração autogerenciadas. Se pensarmos nas crianças caçadoras-coletoras (<xref ref-type="bibr" rid="B34">Gosso, 2004</xref>; Gosso et al., 2005), constatamos que elas têm que adquirir uma quantidade enorme de conhecimento para tornar-se adultos eficientes em sua cultura. No entanto, os adultos não dirigem a educação das crianças ou lhes dizem o que fazer. As crianças estão livres para brincar e para explorar por si próprias de manhã até o entardecer, adquirem as competências da sua cultura e consolidam esse conhecimento brincando, em grupos de várias idades, de atividades culturalmente valorizadas. Os meninos Parakanã da aldeia de Paranowaona, no Pará, brincam de Tekatawa, reunião noturna em que os homens discutem os assuntos da tribo. O seguinte exemplo foi retirado da tese doutorado de Yumi Gosso (2004), desenvolvida sob minha orientação, o título desta tese <italic>PEXE OXEMOARAI</italic>, que significa “vamos brincar?” em Parakanã, foi usado como subtítulo da seção final deste artigo. “Tapiawa (quatro anos, M) usa um pedaço de bambu para fumar e diz que é petyma (cigarro). Traga e passa o cigarro para Suruapa (quatro anos, M). Cruza as pernas e pede o cigarro para seu colega.” (Gosso, 2004, pp. 63-64).</p>
			<p>Embora os adultos não supervisionem suas atividades como ocorre nas cidades, as crianças Parakanã sabem o que os mais velhos fazem, e reproduzem o modelo nas suas brincadeiras imaginativas. Espelham e reconstroem ativamente os valores e hábitos do grupo social em que estão inseridas (<xref ref-type="bibr" rid="B52">Morais &amp; Carvalho, 1994</xref>). Segundo <xref ref-type="bibr" rid="B35">Gosso, Morais e Otta (2007</xref>), por comparação com as crianças Parakanã, que têm a oportunidade de observar o que seus pais fazem, as atividades dos adultos são mais desconhecidas pelas crianças urbanas. Na sua pesquisa de mestrado, baseada na observação de crianças pré-escolares numa escola particular em São Paulo, <xref ref-type="bibr" rid="B51">Morais (1980</xref>) relata que os meninos brincam de pegar o carro, sair para trabalhar e voltar em seguida.</p>
			<p>Recomendo a TED Talk de Peter Gray intitulada “Declínio do Brincar”,<xref ref-type="fn" rid="fn4"><sup>4</sup></xref> em que trata da diminuição das oportunidades de brincar de crianças em ambientes urbanos. Mesmo sem ter todas as oportunidades de uma criança num modo de vida caçador-coletor, ele próprio, nos anos 1950 nos Estados Unidos, reconhece que teve uma infância com muito mais liberdade para brincar do que as crianças têm hoje. Nas últimas décadas, a brincadeira livre diminuiu notavelmente e aumentou o tempo e a prioridade dada à escolarização e às atividades dirigidas por adultos. Isto se deve ao medo maior que os pais têm de deixar as crianças brincando sozinhas fora de casa. Além disso, destaca-se uma política educacional com foco em leitura, escrita e aritmética, em detrimento de educação física e artes, que rouba oportunidades naturais de brincadeira das crianças (<xref ref-type="bibr" rid="B63">Panksepp, 2007</xref>b).</p>
			<p>
				<xref ref-type="bibr" rid="B39">Gray (2011</xref>b) argumenta que a diminuição das oportunidades para brincar está associada ao aumento do risco de patologia em crianças, adolescentes e jovens adultos: ansiedade, narcisismo, sentimentos de desamparo, depressão e suicídio. Isto pode estar correlacionado com a falta de sentimento de controle que as crianças desenvolvem em relação às suas vidas.</p>
			<p>Podemos distinguir <italic>locus de controle interno</italic> - o indivíduo percebe uma relação causal entre o seu próprio comportamento e as recompensas que obtém - e <italic>locus de controle externo</italic> - o indivíduo não vê relação entre suas ações e as consequências (<xref ref-type="bibr" rid="B46">Lefcourt, 2014</xref>; <xref ref-type="bibr" rid="B75">Rotter, 1966</xref>). Nesta linha de raciocínio, o <italic>locus</italic> de controle pode ser modificado pela experiência, e a mudança do modo de vida humano está resultando em mudanças importantes nas crenças que os indivíduos desenvolvem sobre o seu controle sobre eventos da sua vida. A redução da brincadeira e da exploração autogerenciadas tem um papel importante nesse sentido, aumentando a incidência de indivíduos com <italic>locus</italic> de controle externo.</p>
			<p>Outro problema sobre o qual devemos refletir neste contexto é o aumento do diagnóstico de TDAH em ritmo alarmante, associado à prescrição de psicoestimulantes, altamente eficientes em aumentar o foco da atenção e em diminuir problemas de comportamento em sala de aula, mas cujos efeitos sobre o cérebro em crescimento não são adequadamente caracterizados (<xref ref-type="bibr" rid="B9">Barbaresi et al., 2002</xref>; <xref ref-type="bibr" rid="B18">Breggin, 1999</xref>; <xref ref-type="bibr" rid="B32">Faraone, Sergeant, Gillberg, &amp; Biederman, 2003</xref>; <xref ref-type="bibr" rid="B60">Panksepp, 1998</xref>, <xref ref-type="bibr" rid="B64">2008</xref>; <xref ref-type="bibr" rid="B87">Visser, Bitsko, Danielson, Perou, &amp; Blumberg, 2010</xref>).</p>
			<p>Uma tira do cartunista William B. <xref ref-type="bibr" rid="B92">Watterson (2008</xref>), conhecido por sua crítica social, nos faz pensar sobre a infância com Calvin, um garoto de seis anos, e o seu tigre Haroldo. Para as pessoas em geral, Haroldo é só um bicho de pelúcia, mas para Calvin ele é um amigo imaginário, com quem vive suas aventuras. Numa das tiras, no primeiro e no terceiro quadros, Calvin está escrevendo numa folha de papel e dizendo para Haroldo, que aparece grande ao seu lado: ‘<italic>Que? Opa, desculpa. Eu não estava escutando. Olha, preciso mesmo acabar isso</italic>.’ No segundo e no quarto quadros, o menino continua focado em sua tarefa de escrever, mas Haroldo fica pequeno ao seu lado. Ou seja, o tigre vira um mero bicho de pelúcia. Poderíamos pensar que uma criança sob ação de psicoestimulantes é como Calvin, que não vê o amigo imaginário convidando-o para brincar. Sua atenção fica inteiramente focalizada na tarefa escolar.</p>
			<p>Pesquisadores estão usando a brincadeira social turbulenta (BST) em ratos como modelo animal com o objetivo de colaborar para a melhor compreensão do mecanismo de ação de drogas usadas no tratamento de TDAH. Vários pesquisadores, entre eles <xref ref-type="bibr" rid="B13">Beatty, Dodge, Dodge, Whike e Panksepp (1982</xref>), <xref ref-type="bibr" rid="B12">Beatty, Costello e Berry (1984</xref>) e <xref ref-type="bibr" rid="B85">Vanderschuren, Trezza, Griffioen-Roose, Schiepers, Van Leeuwen, De Vries e Schoffelmeer (2008</xref>), vêm mostrando que metilfenidato diminui BST em ratos juvenis de forma quase dependente. Roedores tratados com estas drogas fazem menos convites para brincar e são menos responsivos às iniciativas de outros indivíduos, embora a droga não afete sua atividade locomotora ou exploratória.</p>
			<p>A tese de Jaak <xref ref-type="bibr" rid="B63">Panksepp (2007</xref>b) é que o uso de psicoestimulantes leva as crianças com TDAH a brincar menos, tornando-se mais parecidas com adultos. Isto se daria porque os medicamentos promovem ativação neocortical, e o neocórtex inibe todos os impulsos emocionais de processo primário (<xref ref-type="bibr" rid="B48">Liotti &amp; Panksepp, 2004</xref>). Impulsos lúdicos primários são um direito subcortical que os animais têm ao nascer e que estaria sendo tirado das crianças (<xref ref-type="bibr" rid="B68">Panksepp, Siviy, &amp; Normansell, 1984</xref>). Modelos animais vêm mostrando que a brincadeira é essencial para o desenvolvimento do cérebro social (<xref ref-type="bibr" rid="B72">Pellis &amp; Pellis, 2007</xref>; <xref ref-type="bibr" rid="B73">Pellis, Pellis, &amp; Bell, 2010</xref>) e também que psicoestimulantes usados para tratar TDAH estão entre as drogas mais poderosas de redução do brincar já descobertas (<xref ref-type="bibr" rid="B13">Beatty et al., 1982</xref>; Beatty et al., 1984).</p>
			<p>Podemos pensar que muitas crianças com TDAH, atualmente medicadas com psicoestimulantes, sejam simplesmente crianças normais que têm desejos insatisfeitos excessivos para brincar, e indagar se sintomas de TDAH diminuiriam com suplementação de brincadeira. Segundo Jaak <xref ref-type="bibr" rid="B63">Panksepp (2007</xref>b), quanto mais as crianças puderem se engajar em brincadeira natural durante seu desenvolvimento inicial, mais cedo e mais completamente desenvolverão as funções regulatórias dos lobos frontais que lhes permitirão inibir impulsos, permitindo-lhes “parar, ver, ouvir &amp; sentir”. Em outras palavras, desenvolvendo habilidades executivas que promovem foco em metas, previsão e flexibilidade. Panksep (2007b) relata que tem feito esforços informais para avaliar isso. Na <italic>Memorial Foundation for Lost Children</italic>, em Bowling Green, Ohio, ele vem aconselhando pais de crianças com TDAH a dedicar esforço especial para se engajar em períodos diários de brincadeira turbulenta relaxada e divertida com seus filhos. O feedback dos pais em relação a essa suplementação diária de brincadeira tem sido positivo.</p>
			<p>Peter <xref ref-type="bibr" rid="B39">Gray (2011</xref>b) e Jaak <xref ref-type="bibr" rid="B63">Panksepp (2007</xref>b) nos alertam que temos um problema e ambos propõem a mesma solução geral: devolver a brincadeira para a vida das crianças. Gray (2011b) fala da necessidade de reavaliarmos prioridades, desenvolvermos redes de vizinhos, estabelecermos espaços seguros para as crianças brincarem e, ao mesmo tempo, espaços de aventura, e Panksepp (2007b) chama esses espaços de <italic>santuários para brincar</italic>, inspirado em Platão que, na <italic>República</italic> [seção IV], tratou da importância da brincadeira livre para as crianças pequenas, essencial para que se transformem em cidadãos virtuosos e de boa conduta. Cabe a nós usar criatividade para trazer para o nosso tempo os <italic>santuários para brincar</italic> de Platão. Proposta que está de acordo com o convite-justificativa deste ensaio: permitir que as crianças recuperem a natureza que vem sendo retirada das suas vidas. Quanto mais conhecermos sobre o brincar, mais adequados seremos nas oportunidades que poderemos oferecer às crianças. Precisamos de mais pesquisas sobre este tema na academia, num ambiente intelectual que facilite a colaboração entre etólogos, psicólogos, educadores e neurocientistas, promovendo uma interação bidirecional entre teoria e prática, que possa traduzir rapidamente os resultados da pesquisa em prática, que também pode ajudar a estabelecer direções e refinar hipóteses de pesquisas testáveis.</p>
		</sec>
	</body>
	<back>
		<ref-list>
			<title>Referências</title>
			<ref id="B1">
				<mixed-citation>Ades, C. (1986). Uma perspectiva psicoetológica para o estudo do comportamento animal. Boletim de Psicologia, 36(85), 20-30.</mixed-citation>
				<element-citation publication-type="journal">
					<person-group person-group-type="author">
						<name>
							<surname>Ades</surname>
							<given-names>C.</given-names>
						</name>
					</person-group>
					<year>1986</year>
					<article-title>Uma perspectiva psicoetológica para o estudo do comportamento animal</article-title>
					<source>Boletim de Psicologia</source>
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		<fn-group>
			<fn fn-type="other" id="fn1">
				<label>1</label>
				<p>self-handicapping.</p>
			</fn>
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		<fn-group>
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				<p>having fun.</p>
			</fn>
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			<fn fn-type="other" id="fn3">
				<label>3</label>
				<p>Self-handicapping.</p>
			</fn>
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				<label>4</label>
				<p>Decline of Play. Recuperado de &lt;https://goo.gl/wJAGA3&gt;.</p>
			</fn>
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	</back>
	<sub-article article-type="translation" id="s1" xml:lang="en">
		<front-stub>
			<article-categories>
				<subj-group subj-group-type="heading">
					<subject>Original articles</subject>
				</subj-group>
			</article-categories>
			<title-group>
				<article-title>Psychoethological perspective on play: implications for research and practice</article-title>
			</title-group>
			<contrib-group>
				<contrib contrib-type="author">
					<name>
						<surname>Otta</surname>
						<given-names>Emma</given-names>
					</name>
					<xref ref-type="corresp" rid="c2"><sup>*</sup></xref>
				</contrib>
				<aff id="aff2">
					<institution content-type="original">Universidade de São Paulo, Instituto de Psicologia, Departamento de Psicologia Experimental. São Paulo, SP, Brasil</institution>
				</aff>
			</contrib-group>
			<author-notes>
				<corresp id="c2">
					<label>*</label>Corresponding address: <email>emmaotta@usp.br</email>
				</corresp>
			</author-notes>
			<abstract>
				<title>Abstract</title>
				<p>This study focuses on play from a psychoethological perspective and examines the implications for research and practice. Over the past decades, children are provided with more educational opportunities and more access to adult-led activities, albeit suffering a severe lack of self-directed play. This fact is worrying when we consider the indications in animal models that self-directed play is important for the development of the social brain and emotional self-regulation. This essay represents an invitation-justification for children to recover opportunities for natural play, of which they have been deprived. The more we know about play, the more suitable the opportunities we can offer them will be. We need to conduct further research on this topic, in an intellectual environment that enables collaboration between ethologists, psychologists, educators, and neuroscientists, promoting a bidirectional interaction between theory and practice.</p>
			</abstract>
			<kwd-group xml:lang="en">
				<title>Keywords:</title>
				<kwd>playing</kwd>
				<kwd>social brain</kwd>
				<kwd>development</kwd>
				<kwd>emotion</kwd>
				<kwd>nature</kwd>
			</kwd-group>
		</front-stub>
		<body>
			<sec sec-type="intro">
				<title>Introduction</title>
				<p>This essay deals with the act of playing from the psychoethological perspective and examines the implications of this approach for research and practice regarding a topic that I think is overlooked in the academic field. The term “psychoethological approach” was coined by Walter Hugo de Andrade <xref ref-type="bibr" rid="B29">Cunha - a pioneer of ethology in Brazil (Cunha, 1965</xref>, 2004) - and disseminated by those who followed his inspiring proposal (<xref ref-type="bibr" rid="B7">Arcieri, 1995</xref>; <xref ref-type="bibr" rid="B8">Ardans, 1996</xref>; <xref ref-type="bibr" rid="B3">Ades, 1998</xref>; <xref ref-type="bibr" rid="B47">Lencastre, 2010</xref>; <xref ref-type="bibr" rid="B49">Lucena &amp; Pedrosa, 2014</xref>). Lancastre (2010) points out that psychoethology is the search to conciliate the biological study of behavior with psychological activity. Ades (1986, 1987) believed that psychoethology was an integrated approach to basic behavioral processes, approximating ethology (and behavioral ecology) and experimental psychology, which were developed by means of historically separated paths. This approach has the following programmatic points: 1) selection of ecologically relevant behaviors (functional systems) as an initial focus of analysis; 2) learning as an adaptive phenomenon taking place within functional systems, 3) study of interspecific differences within an ecological reference framework, (4) complementary role of field and laboratory studies, in reciprocal heuristics. Based on this approach, in agreement with Ades (1986, 1987) regarding to its advantages as a generator of research and source of subsidies for a general theory of animal behavior, and inspired by the manifest of Brazilian ethology (Cunha, 1965), I present an invitation-justification for the study of play behavior.</p>
			</sec>
			<sec>
				<title>The reason of the ethologist, fascinated by the observation of behavior</title>
				<p>What is my reasoning for suggesting the study of the playing behavior of animals? The simplest answer I could give is based on the fascination of observing spontaneous behavior that is free from artificial boundaries. It is fun to watch and think about behavior. Reading reports of naturalistic observations that often continue for several years is thought-provoking. I chose two examples to invite readers to think about this topic based on reports of observations made by ethologists: (a) playing with sticks and (b) playing with stones.</p>
				<p>The first example was extracted from an article from <xref ref-type="bibr" rid="B43">Kahlenberg and Wrangham (2010</xref>), which begins with the question: “<italic>would chimpanzees use sticks as if they were dolls?</italic>” In their study, throughout 14 years of observing the behavior of chimpanzees at Kibale National Park in Uganda, the authors recorded over 100 episodes with chimpanzees carrying sticks as if they were dolls. It is interesting to note that this behavior was not observed in other communities, raising the possibility that the chimpanzees were copying a local behavioral tradition. Some episodes were brief, and lasted only a few minutes, but others were longer, lasting more than one hour. The chosen pieces of sticks were different - larger and wider - than the narrow and thin pieces used as tools in the context of termite foraging. Qualitative observations are presented. Some young chimpanzees carried sticks to their nest and slept with them and, on one occasion, the authors observed that the chimpanzees had built a separate nest for the stick. Kakama (8 years), traveling with her pregnant mother, got a piece of stick and carried it for hours, treating it as if it were a baby (e.g., made a nest and put the stick in it). Four months later, two research assistants, who were not aware of the incident, observed a similar behavior from the same individual, who collected another piece of stick. They called it “Kakama’s baby toy”. In another event, the chimpanzee was observed carrying another stick, even beating it as if it were “beating on a baby’s back”, while its mother carried its sick brother. The researchers also noticed young chimpanzees playing a version of “airplane”, laying on their backs with their “stick” and swinging it with arms raised. Mothers play like this with their infants.</p>
				<p>The second example was extracted from a set of articles by Michael <xref ref-type="bibr" rid="B41">Huffman (Huffman, 1984</xref>; Huffman &amp; Quiatt, 1986; <xref ref-type="bibr" rid="B53">Nahallage &amp; Huffman, 2007</xref>, 2012) about play with stones in four groups of <italic>Macaca fuscata</italic> in captivity and in 11 groups in the wild. This form of play consists of repetitive handling of stones: scattering and gathering, rolling from one hand to another, hitting one stone against another with a clacking noise, crashing them into the substrate, rubbing, throwing, dropping them in the water, washing, wrapping with leaves, using a stone as grooming tool, running and throwing. Some episodes were brief (less than a minute), but others were long (20 minutes). This behavior was first observed in Arashiyama as an innovation of a juvenile female, which then spread to other young monkeys and infants of the group. The transmission of this behavior in form of tradition was observed over 25 years, as these individuals became parents and transmitted stone-play to their own offspring. These are only two examples to introduce the topic and to invite readers to reflect on the playing behavior of animals, on the reason to study it, and on the possible value of a comparative approach.</p>
			</sec>
			<sec>
				<title>“Hard” Science versus “Light” Science: Disqualification of play as a research topic by the “serious” man</title>
				<p>Although ethologists study the act of playing and their conclusions are reported in several books (<xref ref-type="bibr" rid="B11">Bateson &amp; Martin, 2013</xref>; <xref ref-type="bibr" rid="B15">Bekoff &amp; Byers, 1998</xref>; <xref ref-type="bibr" rid="B25">Burghardt, 2005</xref>; <xref ref-type="bibr" rid="B71">Pellegrini &amp; Smith, 2005</xref>) and review articles (Burghardt, 2010; <xref ref-type="bibr" rid="B37">Graham &amp; Burghardt, 2010</xref>), this topic of study has been overlooked when compared to others in reference works in the field. Despite the universality of play in animals and humans, observed in children in different cultures (<xref ref-type="bibr" rid="B36">Gosso, Otta, Morais, Ribeiro &amp; Bussab, 2005</xref>; <xref ref-type="bibr" rid="B50">Meirelles, 2007</xref>), there are those who consider it a frivolous and even harmful activity. A review of these points of view can be found in Burghardt (2005). In his book, he mentions that those who interpret play as negative consider it a waste of time and think it may lead people to neglect study and work and even lead to delinquency, game, and crime.</p>
				<p>Regarding animal behavior, it is possible to verify that textbooks, such as the classic <italic>Animal Behavior</italic> by John <xref ref-type="bibr" rid="B6">Alcock (2013</xref>), which is in its 10th edition, do not include chapters on play, although they do include chapters on development. One reason for the relative neglect of play in the academic field is the apparent lack of seriousness of this behavior in its proximal manifestations or functions. Maybe scientists, including ethologists, evolutionary psychologists, and neuroscientists, see play as a nonserious subject and, therefore, not important for study.</p>
				<p>The renowned neuroscientist Jaak Panksepp, who coined the term “affective neuroscience” in 1992, commented on the reaction of the audience to a presentation of his study on play in rats and ultrasonic vocalizations displayed in playful context (Panksepp, Siviy, &amp; Normansell, 1985; Panksepp &amp; Burgdorf, 2003; Panksepp, 2007b):</p>
				<disp-quote>
					<p>When I first presented our work on rat “laughter” . . . at a NIMH symposium in 1998, . . . there was not a single question from a seemingly stony-faced audience of neurobehaviorists. One of the organizers of the meeting took me aside after my session and essentially said, “This research is wonderful. It could be used as a simplified model for positive emotions the way classical conditioning of freezing and startle potentiation is used to study fear… but would you please call it something other than laughter.” I replied, “Yes I could, but then I might be lying, for we do believe this response may be the ancestral source of infantile laughter.” It is a pity when dedicated scholars are discouraged from considering the affective dimensions of brain functions in their study of animal behavior and that they are routinely and strongly encouraged to restrict their discussions to mere behavioral descriptions and learning theory terminologies. (<xref ref-type="bibr" rid="B61">Panksepp, 2005</xref>, p. 67)</p>
				</disp-quote>
				<p>I contacted Jaak <xref ref-type="bibr" rid="B60">Panksepp in 1998</xref>, and started to follow his work ever since (e.g., Panksepp, 1992, 1998; Panksepp &amp; Biven, 2012). He was Emeritus Professor at the Department of Psychology of Bowling Green State University and of Washington State University<xref ref-type="fn" rid="fn5"><sup>5</sup></xref>. I read the book “Affective Neuroscience: The Foundations of Human and Animal Emotions” with much interest, and used it in the “Motivação e Emoção” discipline, which César Ades and I taught for over 30 years on the undergraduate course in Psychology at the Institute of Psychology of University of São Paulo, since it is in line with the psychoethological approach that guides us. I remember my conversations with César (<xref ref-type="bibr" rid="B55">Otta, 2012</xref>, 2015) about the research showing that rats ‘laugh’ - emitting 50-kHz ultrasonic vocalizations (&lt;0,3 s) that the human ear cannot identify, but that can be recorded with equipment and submitted to sonographic analysis - in positive affective situations, such as play (<xref ref-type="bibr" rid="B23">Burgdorf &amp; Panksepp, 2001</xref>; Burgdorf, Kroes, Moskal, Pfaus, Brudzynski, &amp; Panksepp, 2008; <xref ref-type="bibr" rid="B44">Knutson, Burgdorf, &amp; Panksepp, 1998</xref>; Brudzynski &amp; Pniak, 2002), mating (Burgdorf et al., 2008), in response to abusive drugs - e.g., amphetamine - (Burgdorf, Knutson, Panksepp, &amp; Ikemoto, 2001; Thompson, Leonard, &amp; Brudzynski, 2006), and anticipation of rewards (Burgdorf, Knutson, &amp; Panksepp, 2000). They also whine - emitting 22-kHz ultrasonic vocalizations (&gt;0,3 s) - in negative affective situations, such as encounter with a predator (<xref ref-type="bibr" rid="B17">Blanchard, Blanchard, Agullana, &amp; Weiss, 1991</xref>), defeat by a conspecific (<xref ref-type="bibr" rid="B82">Thomas, Takahashi, &amp; Barfield, 1983</xref>), withdrawal of drugs such as alcohol, benzodiazepines, opiates, and psychostimulants (<xref ref-type="bibr" rid="B28">Covington &amp; Miczek, 2003</xref>; <xref ref-type="bibr" rid="B88">Vivian et al., 1994</xref>), and anticipation of aversive stimulation (<xref ref-type="bibr" rid="B27">Choi &amp; Brown, 2003</xref>; <xref ref-type="bibr" rid="B45">Lee, Choi, Brown, &amp; Kim, 2001</xref>). The 50-kHz ultrasonic vocalizations express a positive and appetitive state, and serve as affiliative social signals, while the 22-kHz ultrasonic vocalizations express a negative and aversive state, and serve as a sign of alarm. Having this possibility, rats self-administer playbacks of the 50-kHz vocalizations and avoid playbacks of the 22-kHz vocalizations (Burgdorf et al., 2008). <xref ref-type="bibr" rid="B70">Parsana and Brown (2012</xref>) found that 22-kHz and 50-kHz ultrasonic vocalizations are associated with opposite behavioral responses and with the activation or deactivation of the amygdala.</p>
			</sec>
			<sec>
				<title>Play as a research topic in the light of the whys of ethology: adding a fifth level of analysis</title>
				<p>I remember that, in addition to being a renowned ethologist, César Ades liked to play. At the Memory Center of IPUSP, today the Museum of Psychology, we have several photographs of him (<xref ref-type="fig" rid="f2">Figure 1</xref>). He brought his playful spirit to the classroom and to all his activities. Exploration and play were topics of his classes and research (Ades, 2000, 2012; <xref ref-type="bibr" rid="B33">Gomide &amp; Ades, 1989</xref>). In the pictures below, he appears giving an interview in his office, in a scientific congress, and also in a week of freshmen students of the undergraduate course in psychology of USP, with the mascot of the athletic group and during a sack race.</p>
				<p>
					<fig id="f2">
						<label>Figure 1</label>
						<caption>
							<title>Memories of professor César Ades, researcher and playmate</title>
						</caption>
						<graphic xlink:href="1678-5177-pusp-28-03-358-gf2.jpg"/>
						<attrib>Source: Museum of Psychology of Instituto de Psicologia of Universidade de São Paulo.</attrib>
					</fig>
				</p>
				<p>Having the model of César, I was surprised when I first saw the recommendation “Don’t smile until Christmas!” (<xref ref-type="bibr" rid="B76">Ryan, 1972</xref>). Teachers should start the school year with a serious and uninviting expression regarding the close interaction, the purpose being to maintain the order in the classroom. With César, I learned that, on the contrary, one can smile and laugh in the classroom, and I also learned that the act of playing is a topic worthy of research in the academic field. I think he also encouraged some of my colleagues who studied the play of capuchin monkeys (<xref ref-type="bibr" rid="B74">Resende &amp; Ottoni, 2002</xref>), dolphins (<xref ref-type="bibr" rid="B80">Spinelli, Nascimento, &amp; Yamamoto, 2002</xref>), mice and hamsters (<xref ref-type="bibr" rid="B86">Vieira &amp; Sartorio, 2002</xref>), and Neotropic cormorants and striated herons (<xref ref-type="bibr" rid="B77">Sazima, 2008</xref>). However, there are still few studies on animal playing behavior in Brazil. This is not a usual topic in courses on animal behavior, and it is also an unusual topic in the congresses of the field. This is a theme to be (re)discovered!</p>
				<p>In a research conducted with Paula Gomide, César showed that activities will tend to be perceived more likely as play than as work if children engage in these activities voluntarily. If preschoolers receive rewards for playing with toys on the playground, they will spend less time engaged in these activities than if their only motivation is the intrinsic pleasure of the activity (Gomide &amp; Ades, 1989). Paradoxically, the willingness to play is reduced by external rewards. If the children are free to choose, their engagement with the activity increases, especially if their skill on a challenging task improves with practice (<xref ref-type="bibr" rid="B10">Bateson, 2005</xref>; <xref ref-type="bibr" rid="B31">Deci &amp; Ryan, 1980</xref>).</p>
				<p>According to <xref ref-type="bibr" rid="B81">Spinka, Newberry and Bekoff (2001</xref>), playful behavior allows animals to develop motor and emotional responses to unexpected events in which they experience a sudden loss of control, thus becoming more versatile. To obtain <italic>“training for the unexpected”,</italic> the authors suggest that animals actively seek and create unexpected situations in play by <italic>self-handicapping</italic>; that is, they actively put themselves in disadvantageous positions and situations. Play is made up of sequences in which those involved quickly alternate between well-controlled movements, such as those used in “serious” behavior, and movements that result in a temporary loss of control. This alternation between control and loss of control that characterizes <italic>self-handicapping</italic> generates cognitive demands and a complex emotional state that Spinka, Newberry and Bekoff (2001) call “having fun”. This, of course, is an inference of emotional state indicated by quotation marks. Interested readers can find discussions on inferences of emotional states from behavioral observations that propose the replacement of anthropodenial for critical anthropomorphism (Bekoff, 2006; <xref ref-type="bibr" rid="B25">Burghardt, 2005</xref>; <xref ref-type="bibr" rid="B89">Waal, 1997</xref>, 1999, 2011; <xref ref-type="bibr" rid="B65">Panksepp, 2011</xref>).</p>
				<p>The whys of Ethology can be formulated about play, with the proposal of a fifth level of analysis (Burghard, 2005), in addition to the four whys originally formulated by <xref ref-type="bibr" rid="B84">Tinbergen (1963</xref>): <italic>Cause -</italic> What are the internal and external processes that lead to the performance of playful behavior? <italic>Ontogeny</italic> - How does the act of playing develop during the life of the individual? <italic>Adaptive function</italic> - What are the consequences of play for an animal? <italic>Phylogeny</italic> - How did play evolve from nonplay and what was its evolutionary history? A fifth level of analysis (<xref ref-type="table" rid="t2">Table 1</xref>) was added by Burghard (2005)</p>
				<disp-quote>
					<p>Tinbergen left out one group of phenomena in his four aims: the emotional, experiential, or phenomenological aspects of behavior. He did so because he was trying to gain the acceptance of ethology in a behavioristic Zeitgeist (spirit of the times) in American and European academic psychology . . . The denial of subjective factors did not have an immediately detrimental effect on most ethological research and probably was salutary: There was so much basic work to be done in describing and analyzing the myriad behavior patterns and diversity in courtship, predation, and social organization. One outcome, however, was to ensure that play remained a topic largely neglected by researchers who wanted to be considered “hard” rather than “soft” scientists. In order to rectify the omission of an animal’s “private experience” in the study of behavior, I have promoted a fifth aim to supplement Tinbergen’s four aims . . . . The case for doing this is not repeated here, but new methods, including brain imaging, neuroendocrinology, neurochemistry and pharmacology . . . have led to a greater need to incorporate such issues in ethology and psychology. (pp. 13-14)</p>
				</disp-quote>
				<p>
					<table-wrap id="t2">
						<label>Table 1</label>
						<caption>
							<title>Five levels of analysis of ethology applied to play</title>
						</caption>
						<table>
							<colgroup>
								<col/>
								<col/>
							</colgroup>
							<thead>
								<tr>
									<th align="center">Level of analysis</th>
									<th align="center">Description</th>
								</tr>
							</thead>
							<tbody>
								<tr>
									<td align="center">Cause</td>
									<td align="center">Internal and external factors underlying behavior</td>
								</tr>
								<tr>
									<td align="center">Ontogeny</td>
									<td align="center">Patterns and processes of behavior change throughout the development</td>
								</tr>
								<tr>
									<td align="center">Adaptive Function</td>
									<td align="center">Contribution of behavior to the survival of individuals and groups, reproductive and inclusive fitness</td>
								</tr>
								<tr>
									<td align="center">Phylogeny</td>
									<td align="center">Historical patterns of behavioral change across generations and taxa</td>
								</tr>
								<tr>
									<td align="center">Private experience</td>
									<td align="center">Subjective experience. Heterophenomenology.</td>
								</tr>
							</tbody>
						</table>
						<table-wrap-foot>
							<fn id="TFN2">
								<p>Source: Adapted from <xref ref-type="bibr" rid="B25">Burghardt, 2005</xref>
								</p>
							</fn>
						</table-wrap-foot>
					</table-wrap>
				</p>
				<p>
					<xref ref-type="bibr" rid="B25">Burghardt (2005</xref>) proposes five criteria to characterize play: <italic>incomplete functionality</italic> - The behavior is not completely functional in the way or the context in which it is expressed, including elements that do not contribute to current survival. In fact, it is hard to see functionality when one observes a <italic>Macaca fuscata</italic> individual who spends 20 minutes scattering and gathering stones (<xref ref-type="bibr" rid="B41">Huffman, 1984</xref>); <italic>motivational state</italic> - The behavior is spontaneous, voluntary, pleasurable, rewarding by itself, and autotelic; <italic>play differs from strictly functional expressions of behavior</italic> - It is structurally or temporally different from the related serious behaviors: incomplete (with inhibited or absent final elements), exaggerated, clumsy, premature. That is, it involves modified behaviors regarding the form, sequence, or target, considering its serious counterparts; <italic>the behavior is repeated</italic> - the behavior is performed repeatedly, in a similar way, but not rigidly stereotyped, during at least part of the animal’s lifespan; (5) <italic>Motivational field</italic> - The behavior is initiated when the animal is in a “relaxed field” - e.g., the animal is not under stress of physical danger, disease, adverse weather conditions, social instability, or intense competitive systems (e.g., fear).</p>
				<p>There is evidence that the risk of predation indicated by cat odor suppresses play in juvenile rats (<xref ref-type="bibr" rid="B40">Hubbard, Blanchard, Yang, Markham, Gervacio, Chun-I, &amp; Blanchard, 2004</xref>; <xref ref-type="bibr" rid="B79">Siviy, Harrison, &amp; McGregor, 2006</xref>). <xref ref-type="bibr" rid="B60">Panksepp (1998</xref>) showed that this suppression was specific, only found when he placed cat hair in the space where the juveniles were playing, but not when he placed dog hair on same spot. Siviy (2010) concludes that play seems to be resilient in the face of adversity in juvenile rats. It is as if the brain had evolved to see an adaptive advantage in stopping play when there is risk of predation, but, after the risk passes, the juveniles resume playing, as if the brain did not see an adaptive reason to continue maintaining feelings of fear and anxiety. However, we may be wrong about what is a threat and predict a suppression of play when no suppression occurs. This is what Stuart <xref ref-type="bibr" rid="B19">Brown (2009</xref>) shows with a remarkable sequence of photos of a bear and a dog playing, in a time of food shortage. Instead of becoming prey, the dog, much smaller than the bear, turned out to be a partner in a long and apparently relaxed play bout. In this case, a <italic>playful mood</italic> rather than a <italic>serious mood</italic> predominated. The bear behaved in accordance with the principles described by Mark <xref ref-type="bibr" rid="B16">Bekoff and Jessika Pierce (2010</xref>) in their article entitled “The ethical dog”. It considered the ability of its partner, creating and maintaining a relationship of equality, which involves: (1) <italic>Role reversal</italic> - a dominant animal performs an action during play that normally would not occur during real aggression, and the weaker animal can “attack”; (2) <italic>Self-handicapping</italic> - the stronger animal does not bite its play partner as strongly as it would be able to, nor plays so vigorously as it could; (3) <italic>Meta-communication</italic> - an animal seems to recognize that its partner is simulating and indicates that it is also simulating. Besides stances, there is a playful face that signals that a particular behavioral sequence is playful and not aggressive.</p>
				<p>Interestingly, <xref ref-type="bibr" rid="B58">Palagi and Cordoni (2012</xref>) showed that the social play of bonobos (<italic>Pan paniscus</italic>) and common chimpanzees (<italic>Pan troglodytes</italic>) is similar when they are infants. However, during the juvenile period, the play of bonobos is less frequently transformed in aggression, it lasts longer, and may involve more than two partners simultaneously. As adults, bonobos continue to play, but chimpanzees do not, which is probably due to the difference in social tolerance between the two species (Palagi, 2006; Palagi &amp; Cordoni (2012).</p>
			</sec>
			<sec>
				<title>PEXE OXEMOARAI: invitation-justification to reevaluate our priorities</title>
				<p>I invite you now to think about our own species, from the context of the psychoethological perspective presented above. I share Peter <xref ref-type="bibr" rid="B39">Gray’s (2011</xref>a) point of view that human children were designed by natural selection to acquire culture by self-managed play and exploration. If we think about hunter-gatherer children (<xref ref-type="bibr" rid="B34">Gosso, 2004</xref>; Gosso et al., 2005), we find out that they have to acquire a huge amount of knowledge to become efficient adults in their culture. However, the adults do not guide the education of children or tell them what to do. Children are free to play and explore everything from morning until evening. They acquire the skills of their culture and consolidate this knowledge whilst playing in groups of children of various ages, performing culturally valued activities. The Parakanã boys from Paranowaona village, in the state of Pará, play “Tekatawa”, the night meeting in which the men discuss the affairs of the tribe. The following example was taken from the doctoral thesis of Yumi Gosso (2004), which was developed under my supervision. I used the title of that thesis, PEXE OXEMOARAI, which means “let’s play?” in Parakanã, as the subhead of this final section of my article. “Tapiawa (four years old, M) uses a piece of bamboo to smoke and says it is a ‘petyma’ (cigarette). He smokes and passes the cigarette to Suruapa (four years old, M). He crosses his legs and asks for the cigarette back from his playmate” (Gosso, 2004, p. 63-64).</p>
				<p>Although adults do not supervise their activities, as they do in the cities, Parakanã children know what they do and replicate the model in their imaginative plays. They actively mirror and rebuild the values and habits of the social group in which they are inserted (<xref ref-type="bibr" rid="B52">Morais &amp; Carvalho, 1994</xref>). According to <xref ref-type="bibr" rid="B35">Gosso, Morais and Otta (2007</xref>), when compared with Parakanã children, who have the opportunity to observe what their parents do, urban children are more unaware of their parents’ activities. During her master’s research, based on the observation of preschool children at a private school in São Paulo, Morais (1980) reports on boys’ play, namely picking up their car, going out to work, and then coming back.</p>
				<p>I recommend the TED Talk by Peter Gray entitled “Decline of Play”,<xref ref-type="fn" rid="fn6"><sup>6</sup></xref> in which he deals with children’s reduction of opportunities for play in urban environments. Even without having all the opportunities that a child has in the context of the hunter-gatherer way of life, he acknowledges that in the America of the 1950’s he had a childhood with a lot more freedom to play than children have today. In recent decades, the free play of children has considerably decreased, while the time and priority given to education and adult-led activities has increased. This is due to greater fear parents have about children›s safety preventing them from playing outside alone. In addition, an educational policy that focuses on reading, writing and arithmetic stands out, to the detriment of physical education and arts, which steals away children’s natural opportunities for playing (<xref ref-type="bibr" rid="B62">Panksepp, 2007</xref>).</p>
				<p>
					<xref ref-type="bibr" rid="B39">Gray (2011</xref>b) argues that this reduction of opportunities to play is associated with an increased risk of pathology in children, adolescents, and young adults: anxiety, narcissism, feelings of helplessness, depression, and suicide. This can be correlated with the feeling of loss of control that children develop regarding their lives. We can distinguish <italic>internal locus of control</italic> - the individuals perceive a causal relationship between their own behavior and the rewards they get - and <italic>external locus of control</italic> - the individuals do not see a connection between their actions and the consequences (<xref ref-type="bibr" rid="B46">Lefcourt, 2014</xref>; <xref ref-type="bibr" rid="B75">Rotter, 1966</xref>). Along with this line of reasoning, the locus of control can be modified by experience, and the change in the human way of life results in major changes in the beliefs that individuals develop regarding their control over the events of their life. The reduction of self-managed play and exploration has an important role in this sense, thereby increasing the incidence of individuals with external locus of control.</p>
				<p>Another issue that we must address in this context is the increase in the diagnosis of attention deficit hyperactivity disorder (ADHD) at an alarming rate, which is associated with the prescription of psychostimulants, which are highly efficient at increasing the focus of attention and reducing behavior problems in the classroom, but whose developmental effects on the growing brains are not adequately characterized (<xref ref-type="bibr" rid="B9">Barbaresi et al., 2002</xref>; <xref ref-type="bibr" rid="B18">Breggin, 1999</xref>; <xref ref-type="bibr" rid="B32">Faraone, Sergeant, Gillberg, &amp; Biederman, 2003</xref>; <xref ref-type="bibr" rid="B60">Panksepp, 1998</xref>, 2008; <xref ref-type="bibr" rid="B87">Visser, Bitsko, Danielson, Perou, &amp; Blumberg, 2010</xref>).</p>
				<p>A comic strip by cartoonist William B. <xref ref-type="bibr" rid="B92">Watterson (2008</xref>), known by his social criticism, makes us think about childhood with Calvin, a six-year-old boy, and his tiger, Hobbes. For people in general, Hobbes is only a stuffed animal, but for Calvin he is an imaginary friend, with whom he lives his adventures. In one of the strips, in the first (and third) panels, Calvin appears writing on a piece of paper and saying to Hobbes, who appears at his side: ‘<italic>What? Oh, sorry. I wasn’t listening. Look, I really need to finish this’.</italic> In the second (and fourth) panels, Calvin remains focused on his task of writing, but Hobbes gets small at his side. That is, the tiger becomes a mere stuffed animal. We could think that a child under the action of psychostimulants is as Calvin, who does not see his imaginary friend inviting him to play. His attention is fully focused on the school task.</p>
				<p>Researchers are using rough-and-tumble play (RTP) in rats as an animal model, with the aim of contributing to a better understanding of the action mechanism of the drugs used in the treatment of ADHD. Several researchers, including <xref ref-type="bibr" rid="B13">Beatty, Dodge, Dodge, Whike, and Panksepp (1982</xref>), Beatty, Costello, and Berry (1984), and <xref ref-type="bibr" rid="B85">Vanderschuren, Trezza, Griffioen-Roose, Schiepers, Van Leeuwen, De Vries, and Schoffelmeer (2008</xref>), have found a dose-dependent RTP suppressant effect of methylphenidate in juvenile rats. Rats treated with this drug make less play invitations and are less responsive to the invitations of others, although the drug does not affect their locomotive or exploratory activity.</p>
				<p>Jaak <xref ref-type="bibr" rid="B63">Panksepp (2007</xref>b) states that use of psychostimulants leads children with ADHD to play less and become more like adults. This would take place because psychostimulants promote neocortical activation, and the neocortex inhibits all <italic>primary</italic>-<italic>process emotional</italic> urges (<xref ref-type="bibr" rid="B48">Liotti &amp; Panksepp, 2004</xref>). Primary playful urges are a subcortical birthright of animals but <italic>children’s rights to play</italic> are <italic>constrained</italic> in urban societies (Panksepp, Siviy, &amp; Normansell, 1984). Animal models have shown that play is essential for the development of the social brain (<xref ref-type="bibr" rid="B72">Pellis &amp; Pellis, 2007</xref>; Pellis, Pellis, &amp; Bell, 2010) and that psychostimulants used to treat ADHD are among the most powerful drugs to reduce play ever discovered (<xref ref-type="bibr" rid="B13">Beatty et al., 1982</xref>; Beatty et al., 1984).</p>
				<p>We may think that many children with ADHD, currently medicated with psychostimulants, are only normal kids who have excessive unfulfilled desires to play. What we can ask ourselves is whether ADHD symptoms would decrease with a supplementation of play. According to Jaak <xref ref-type="bibr" rid="B63">Panksepp (2007</xref>b), the more the children can engage in natural play during their initial development, the sooner and more thoroughly will they develop the regulatory functions of the frontal lobes that will allow them to inhibit impulses, enabling them to “stop, look, listen &amp; feel”, in other words, to develop executive skills that promote a focus on goals, forethought, and flexibility. Panksepp (2007b) reports that he has made informal efforts to evaluate this. At the Memorial Foundation for Lost Children, in Bowling Green, Ohio, he has been advising parents of children with ADHD to dedicate a special effort to engage in daily periods of relaxed and funny rough-and-tumble play with their children. The parents’ feedback about this daily supplementation of play has been positive.</p>
				<p>Peter <xref ref-type="bibr" rid="B39">Gray (2011</xref>b) and Jaak <xref ref-type="bibr" rid="B63">Panksepp (2007</xref>b) warn us that we have a problem and both propose the same general solution: to give play back to children’s lives. Peter Gray (2011b) speaks of the need to reevaluate priorities, to develop social networks of neighbors, and create safe spaces filled with adventure. Jaak Panksepp (2007b) calls these spaces <italic>play sanctuaries</italic>, inspired by Plato’s <italic>Republic</italic> [section IV], which dealt with the importance of free play to young children, essential for them to become well conducted and virtuous citizens. It is up to us to use creativity to bring Plato’s <italic>play sanctuaries</italic> to our time. This proposal is in line with the invitation-justification of this essay: to allow children to recover the nature that has been removed from their lives. The more we know about play, the more appropriate the opportunities we can offer children will be. We need to conduct further research on this topic, in an intellectual environment that enables collaboration between ethologists, psychologists, educators, and neuroscientists, thereby promoting a bidirectional interaction between theory and practice that can quickly translate research results into practice. Practice can also give valuable insights for further research and help us to refine our research hypotheses.</p>
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					<p>Dr. Jaak Panksepp, known worldwide as the proponent of Affective Neuroscience, passed away on April 18, 2017</p>
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					<p>Decline of Play http://www.youtube.com/watch?v=Bg-GEzM7iTk</p>
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