Behaviour 153 (2016) 1005–1011 brill.com/beh Editorial Looking at natural peace through Niko Tinbergen’s lens Peter Verbeek a,b,∗ and Elisabetta Palagi c,d,∗ a Department of Anthropology, University of Alabama at Birmingham, Birmingham, AL, USA b Miyazaki International College, 1405 Kano, Kiyotake, Miyazaki 889-1605, Japan c Natural History Museum, University of Pisa, Via Roma, 79, 56011, Calci, Pisa, Italy d Institute of Cognitive Sciences and Technologies, Unit of Cognitive Primatology and Primate Center, CNR, Via Aldrovandi 16b, 00197, Rome, Italy *Corresponding authors’ e-mail addresses: [email protected]; [email protected] In March 2013, 53 scientists from three continents and a range of disciplines, including anthropology, ethology, evolutionary biology, neuro- science, political science and psychology, attended a week-long workshop at the Lorentz Center of Leiden University entitled ‘Obstacles and Catalysts of Peaceful Behavior’ (Figure 1). The meeting followed in the footsteps of a symposium and roundtable at the XXV International Ethological Conference in Vienna in 1997 on post-conflict behaviour (de Waal, 2000) that inspired the edited volume ‘Natural conflict resolution’ (Aureli & de Waal, 2000). The Leiden meeting expanded the concept of natural conflict resolution into a concept of natural peace. Peace is seen here as behavioural process and includes, but is not limited to, mutually beneficial cooperation, helping, shar- ing, and limiting aggression and restoring tolerance in its aftermath. How and why did these peaceful behaviours evolve and persist? What is their function and how do they develop? Following up on the discussions in Leiden we in- vited 14 participants at the Leiden meeting and 17 other experts in the field to offer some answers to these questions by means of a contribution to this special issue. While each article stands on its own in terms of its particu- lar contribution to the field, the articles complement each other by offering views from different disciplines within the framework of Tinbergen’s four questions. © Koninklijke Brill NV, Leiden, 2016 DOI 10.1163/1568539X-00003406 1006 Looking at natural peace through Niko Tinbergen’s lens Figure 1. Participants at the Lorentz Center workshop ‘Obstacles and Catalysts of Peace- ful Behavior’ (http://www.lorentzcenter.nl/lc/web/2013/527/info.php3?wsid=527&venue= Oort). This figure is published in colour in the online edition of this journal, which can be accessed via http://booksandjournals.brillonline.com/content/journals/1568539x. Tennyson’s “nature red in tooth and claw” and Huxley’s ‘gladiator show’ reflect a view of animal life as unmitigated violent competition. This view has been tenacious in steering research on animal behaviour toward a fo- cus on how individuals maximize their fitness through competition. This approach is incomplete, however. Biologists have long known that coop- eration is a significant life force and have studied it at multiple levels of biological organization, from cooperating organelles within a single cell to ecological mutualisms among species. Renowned zoologist and geneticist Lynn Margulis commented in this context, “Life did not take over the globe by combat, but by networking”, in other words, by cooperation, interaction, and mutual dependence among living organisms (Margulis & Sagan, 2001). Research conducted during the past four decades shows that mutually bene- ficial peaceful behaviours appear in a wide range of species. Explaining how and why such peaceful behaviours have evolved and persist, what triggers them, and how they develop, presents a challenge for behavioural science. Niko Tinbergen anticipated this challenge and called for the application of ethology’s questions and methods (Tinbergen, 1963) to the study of “War.