Canine Review Canis sensitivus: Affiliation and dogs’ sensitivity to others’ behavior as the basis for synchronization with humans? Charlotte Duranton a, b, * , Florence Gaunet a a Laboratoire de Psychologie Cognitive, CNRS, Aix-Marseille Université, UMR 7290, Marseille, France b AVA Association, Cuy-Saint-Fiacre, France article info Article history: Received 30 January 2015 Received in revised form 5 August 2015 Accepted 18 August 2015 Available online 5 September 2015 Keywords: domestic dog behavioral synchronization behavioral mimicry dog-human synchronization dog-human affiliation abstract One widely studied phenomenon in behavioral sciences is the ability of 2 individuals to behave in a synchronous way, which has links with affiliative relationships and an adaptive role in increasing fitness. Behavioral synchrony is found in various social species, but has been very little studied at the inter- specific level. The unique relationship of humans and dogs deserves to be studied from this perspective. This article reviews present knowledge about dogs’ sensitivity to other dogs’ and humans’ behaviors. The conclusions are that (1) dogs are sensitive to other dogs’ and humans’ direct behavior, and adjust their own behaviors accordingly; (2) dogs use some information from third-party interactions, and adjust their behavioral response according to the outcome of the interactions; and (3) some recent data suggest that dogs are sensitive to humans’ emotional cues, that they show social referencing toward humans, and emphasize the strong affiliative bond between dogs and their owners. This finding suggests that dogs can be considered as an appropriate biological model to study interspecies synchronization with humans. We propose that dogs could mirror at least their owners during day-to-day situations and encourage further research in this field. Ó 2015 Elsevier Inc. All rights reserved. Introduction Being synchronized 1 with other individuals can be defined by 3 complementary characteristics, 3 types of synchrony. First, the temporal aspect of synchronization (also called temporal syn- chrony), is defined as switching actions at the same time (Dostálková and  Spinka, 2007; Lakin et al., 2003). The actions/ac- tivities/events can be identical or different (i.e., if all individuals in a group switch from inactivity to activity, even if they are performing different actionsdone switching from resting to scratching itself, another from resting to yawning, and the third from resting to standing up and moving), but the important feature is the timing. Second, the behavioral aspect of synchronization, often called ac- tivity synchrony, is defined as performing the same behaviors as others in a short lap of time. This type of synchronization is also often called behavioral matching, allelomimicry or nonconscious behavioral mimicry in the literature (Chartrand and Barg, 1999; Chartrand and Lakin, 2013; Gautrais et al., 2007; Lakin et al., 2003; Louwerse et al., 2012). Third, the local aspect of synchroni- zation, named local synchrony, is defined as being in the same place at the same time (Bertram, 1980; King and Cowlishaw, 2009). These aspects are often combined together and/or cited under the name of synchronization in a broad sense (for each temporal/behavioral/ local synchrony alone or combined together), as suggested by Louwerse et al. (2012), and we chose to do the same in the following parts of the present review. Synchronization is widespread among live beings and has various adaptive values. Indeed, being synchronized with others increases the fitness of offspring by decreasing the pressure of predation (Yasaka et al., 2003), increases the chances of survival of each member by avoiding predators (Conradt and Roper, 2000; Fernandez et al., 2003), increases foraging efficiency (King and Cowlishaw, 2009; Stone et al., 2003), and increases social * Address for reprint requests and correspondence: Duranton Charlotte, Labo- ratoire de Psychologie Cognitive, CNRS, Aix-Marseille Université, UMR 7290, 3 place Victor Hugo, CS 80249, Bât. 9, Case D,13331 Marseille Cedex 03, France, Tel: þ33 4 13 55 09 60; Fax: þ33 4 13 55 09 65. E-mail address: charlotte.duranton@cegetel.net (C. Duranton). 1 In this review, we chose to focus only on nonconscious synchronization. Indeed, conscious synchronization is a full field of study, leading to more complex phe- nomena such as cooperation, but we did not review it. Contents lists available at ScienceDirect Journal of Veterinary Behavior journal homepage: www.journalvetbehavior.com http://dx.doi.org/10.1016/j.jveb.2015.08.008 1558-7878/Ó 2015 Elsevier Inc. All rights reserved. Journal of Veterinary Behavior 10 (2015) 513e524