Do animals feel jealousy?
Charles Darwin thought so. In The Descent of Man, he wrote that a dog will become jealous “of his master’s affection, if lavished on any other creature.”
But, since then, scientists have disagreed. Some thought only humans could exhibit the emotion.
Many pet owners are in no doubt; Your correspondent, for example, is quite certain that one of his cats turns into a green-eyed monster if her brother gets too much attention.
Read the whole story: Forbes