A nine-month study hints that dogs could possibly feel a human-like emotion.
A study by a psychology professor at the University of California, San Diego supports this basic theory.
Dogs and their owners were videotaped, while the human played with stuffed animals.
In almost all the cases, the dogs tried to get the attention of their owners by pushing or even snapping at the phony pooch.
But other experts, like those at the American College of Veterinary Behaviorists, wouldn't call the behavior jealousy.
They also question whether dogs feel shame.
The study is published in the journal PLOS ONE.