Dogs Mentally Represent Jealousy-Inducing Social Interactions

Abstract

Jealousy may have evolved to protect valuable social bonds from interlopers, but some researchers have suggested that it is linked to self-awareness and theory of mind, leading to claims that it is unique to humans. We presented dogs ( N = 18; 11 females; age: M = 4.6 years, SD = 1.9) with situations in which they could observe an out-of-sight social interaction between their owner and a fake dog or between their owner and a fleece cylinder. We found evidence for three signatures of jealous behavior in dogs: (a) Jealousy emerged only when the dog’s owner interacted with a perceived social rival, (b) it occurred as a consequence of that interaction and not because of the mere presence of a conspecific, and (c) it emerged even for an out-of-sight interaction between the dog’s owner and a social rival. These results support claims that dogs display jealous behavior, and they provide the first evidence that dogs can mentally represent jealousy-inducing social interactions.

Pet dogs’ Behavioural Reaction to Their Caregiver’s Interactions with a Third Party: Join in or Interrupt?

“…The dog behaviours interpreted as jealousy were, for example, squeezing in-between the human–dog interaction (blocking the caregiver from the other dog/social rival), trying to separate the caregiver from the other dog, reacting aggressively by growling, snarling, barking, launching and snapping at the other dog, and trying to regain the caregiver’s attention and affection. Similar to these reports and other behavioural studies investigating jealousy-like behaviours in dogs, we also found that the dogs responded in a rather variable way to a third party their human caregiver was interacting with [ 7 , 8 , 23 ].…”

“…Another study using various fake dogs [ 23 ] also found that dogs socially investigated the fake dogs by sniffing the anal region and the muzzle (83% in study 1: with furry fake dog, 78% in study 2: with plastic dog). Moreover, very recently, another study [ 7 ] also showed that 14 out of 15 subject dogs (93%) displayed conspecific-directed behaviours, i.e., sniffed the fake dogs’ (facial and) anal regions when being unleashed after the last test trial (of only observing the interactions), and thus, claimed that they perceived the fake dogs as real dogs [ 7 ]. This is in line with the fact that anogenital sniffing is a common (social) behaviour in dogs to identify the sex or identity of another dog, e.g., when approaching or greeting conspecifics, and hence, might indicate that dogs perceived the fake dog as a real dog or social rival, at least before finally getting closer or physically interacting with it [ 8 , 58 , 59 , 60 ].…”

“…In line with the above mentioned reports, it has been suggested that pet dogs may be a promising model species to investigate jealousy in non-human animals [ 6 , 7 , 8 , 9 ]. Given that pet dogs closely cohabit with humans, form strong and stable attachment bonds with them which highly resemble the human mother–child bond [ 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 ], and typically have plenty of opportunities to observe their caregiver engaging in positive social interactions with others, there are many occasions to witness them in situations that typically evoke jealous reactions in human children [ 19 , 20 , 21 ].…”

“…Some authors reported distinctive jealousy-like behaviours such as blocking the social rival (fake or real dog) from approaching the caregiver or getting (sometimes aggressively) between them during their interaction, presumably to intervene or try to separate their valuable caregiver from the intruder [ 6 , 8 ]. Using a different approach, the most recent study presented human–fake dog interactions to leashed pet dogs while measuring their pull force towards the scene [ 7 ]. Leash pulling was measurably stronger when the caregiver engaged in such an interaction, which was interpreted as evidence for jealousy.…”