A team of neurobiologists from the University of Vienna (Austria) has confirmed what dog owners already suspected: that these animals can feel envy and react negatively when they perceive that they are treated worse than others.
The study authors taught several dogs to extend the leg, which they willingly obeyed, even without receiving a treat in return. But when they started giving bread or a sausage to some dogs before others to whom they had given nothing, they seemed to feel aggrieved: they yawned and scratched themselves or refused to participate in the game.
