Behaviour 2019
Dogs mentally represent jealousy inducing situations
Byung-Chan Lim, Amalia, P. M. Bastos, Patrick, D. Neilands, Rebecca, S. Hassall, Alex, H. Taylor. University of Auckland, Auckland, , New Zealand

Jealousy is a complex emotion thought to have evolved to protect valuable social bonds. As dogs live in close proximity with humans, jealousy may have developed to protect such relationships. Studies on how jealous behaviour in dogs are expressed are limited by alternate explanations and have yielded mixed results. Utilising a novel pulling-force paradigm, the current study aimed to find three signatures of human-like jealousy in dogs: that jealous behaviour should emerge: (1) only when the relationship is threatened by a social rival, (2) due to the interaction between the owner and interloper, rather than due to the presence of a conspecific, and (3) when the owner-rival interaction is not directly visible to the subject. We found dogs pull with greater force when their owners interacted with a hidden realistic stuffed dog rather than a fleece cylinder. Furthermore, in a control trial where owner-rival interaction was directly visible, there was no difference in pulling force than when the interaction was not visible. The results support claims that dogs display jealous behaviour and provides the first evidence that dogs can mentally represent jealousy-inducing interactions.