Via IFLScience, ‘While many dog owners will tell you that their canine companion gets jealous if attention is diverted away from them, given the complex cognitions thought to be involved in this emotion many have assumed that jealousy is in fact unique to humans. Some have even proposed that jealousy requires self-reflection and the ability to understand conscious intentions. However, much research into this area has primarily focused on jealousy within romantic relationships over infidelity, neglecting to investigate other forms of this emotion, especially in other species.

Published in the journal PLOS ONE, researchers describe the first experimental test of jealousy in dogs which found that these animals displayed jealous behaviors when attention from owners was directed towards a fake pooch. This suggests that a form of this emotion exists in at least one other social species alongside humans.’