Original Article Exploring the evolutionary foundations of empathy: consolation in monkeys Elisabetta Palagi a, b , Stefania Dall’Olio c , Elisa Demuru a, d , Roscoe Stanyon c, ⁎ a Natural History Museum, University of Pisa, Via Roma 79, Calci, Pisa, Italy b Unit of Cognitive Primatology and Primate Center, Institute of Cognitive Sciences and Technologies CNR, via Ulisse Aldrovandi 16/b, Rome, Italy c Anthropology Laboratories, Via del Proconsolo 12, Department of Biology, University of Florence, Italy d Department of Bioscience, University of Parma, Parco Area delle Scienze, 11/a, 43124, Parma, Italy abstract article info Article history: Initial receipt 6 March 2013 Final revision received 4 April 2014 Available online xxxx Keywords: Macaca fuscata Macaca tonkeana Third-party affiliation Social constraints Victim protection Anxiety alleviation Sympathetic concern Unsolicited third-party affiliation occurs when victims of aggression receive a spontaneous affinitive contact from a bystander. Consolation is a specific type of unsolicited third-party affiliation showing two key components: 1) it alleviates distress in the victims and 2) is preferentially directed towards friends. Consolation was thought to be present only in humans, chimpanzees, and bonobos linked to their higher cognitive and empathic abilities. Previous investigations in monkeys found unsolicited third-party affiliation in only two species with no evidence of consolation. In the research presented here we set out to test a number of hypotheses concerning third-party affiliation in Macaca fuscata and M. tonkeana, two species that differ remarkably for social style. M. fuscata is despotic, while M. tonkeana is one of the most tolerant species of macaques. We found no evidence of unsolicited third-party affiliation in M. fuscata, but it was present in M. tonkeana. In this species we found that unsolicited third-party affiliation reduced anxiety (measured by scratching) in the victims and was directed towards friends and especially towards females who experienced higher levels of anxiety compared to males. Third-party affiliation also occurred more frequently in the absence of reconciliation. All the key features used to recognize consolation in humans and great apes are present in M. tonkeana making it difficult not to conclude that consolation exists in this species. Since consolation is most often considered to be driven by empathy, our results suggest that Tonkean macaques are capable of empathetically reacting to the victim’s state of anxiety. Our results support the Social Constraints Hypothesis showing that the degree of tolerance is a key factor in the expression of consolation. Investigating behavioral patterns driven by even the most basic forms of empathy requires the choice of an appropriate species and Macaca tonkeana is a good model to investigate the full phylogenetic range, evolutionary depth, and origin of empathy in primates. © 2014 Elsevier Inc. All rights reserved. 1. Introduction For social species, including humans, aggression can have dramatic consequences not only for the individuals involved but also for the whole group (Aureli & de Waal, 2000; Esteban, Mayoral, & Ray, 2012). Conflict can generate further conflicts and/or can affect affiliative interactions in the group (Barash & Lipton, 2011; de Waal, 2000; Ellemers, 2012; Palagi & Cordoni, 2009; Watts, Colmenares, & Arnold, 2000). Reconciliation, defined as an affinitive interaction between former opponents in the first minutes after a fight, is an effective conflict resolution mechanism (de Waal & Roosmalen, 1979). Reconciliation reduces the probability of further attacks, limits anxiety in the victim, and restores the benefits associated with a good relationship (Aureli, Cords, & Van Schaik, 2002). After a conflict, victims can also receive a friendly, spontaneous contact from a bystander not involved in the aggression, a phenomenon labeled “unsolicited bystander affiliation” or “unsolicited third-party affiliation” (Fraser, Koski, Wittig, & Aureli, 2009; Romero, Castellanos, & de Waal, 2010). This first spontaneous post-conflict affiliative contact from a third-party to the victim was called consolation and was reported for great apes and humans (chimpanzees: Fraser & Aureli, 2008; Koski & Sterck, 2007; Kutsukake & Castles, 2004; Palagi, Cordoni, & Borgognini Tarli, 2006; Romero & de Waal, 2010; Wittig & Boesch, 2003, 2010; gorillas, Cordoni & Palagi, 2007; bonobos, Clay & de Waal, 2013a,b; Palagi & Norscia, 2013; Palagi, Paoli, & Tarli, 2004; humans, Eisenberg, 1992; Fujisawa, Kutsukake, & Hasegawa, 2006). Consolation reduces the victim’s anxiety, is provided by friends and is apparently based on empathy. Some researchers skeptical of the empathic basis of consolation still prefer to use the more neutral term, “unsolicited bystander affiliation” (Call, Aureli, & de Waal, 2002). Evolution and Human Behavior xxx (2014) xxx–xxx ⁎ Corresponding author. Laboratory of Anthropology, Department of Biology, via del Proconsolo 12, 50122 Florence, Italy. Tel.: +39 0552757738. E-mail address: roscoe.stanyon@unifi.it (R. Stanyon). http://dx.doi.org/10.1016/j.evolhumbehav.2014.04.002 1090-5138/© 2014 Elsevier Inc. All rights reserved. Contents lists available at ScienceDirect Evolution and Human Behavior journal homepage: www.ehbonline.org Please cite this article as: Palagi, E., et al., Exploring the evolutionary foundations of empathy: consolation in monkeys, Evolution and Human Behavior (2014), http://dx.doi.org/10.1016/j.evolhumbehav.2014.04.002