Can a dog be jealous?

Whether humans alone experience complex emotions like jealousy or envy remains hotly debated, partly because of the difficulty of measuring them without a verbal report. Cook, Berns and colleagues use functional brain imaging to identify in dogs neural responses very similar to those evoked by jealousy in humans. When dogs see their caregiver reward a facsimile dog, their amygdala is activated and the strength of this response predicts aggressive behavior — just as jealousy leads to aggression in humans. The authors conclude that dogs feel something very similar to human jealousy. This novel and creative study tackles one of the most vexing challenges in neuroscience — understanding the unstated thoughts and feelings of others — with practical applications that go beyond getting closer to man’s best friend. The issue of whether a dog can be jealous nevertheless remains far from settled, as we discuss below