A new study of chimpanzee and bonobo groups at zoos reveals similar levels of aggression. However, scientists found stark sex-based differences between the species.

Here are 10 animals that have some of the highest levels of testosterone and the impact it has on their behavior and characteristics.

A prolonged and unblinking stare is a known indicator of stress and potential aggression in dogs. In play, dogs break eye ...

Scientists studying 1,300 golden retrievers have uncovered genetic clues explaining why some dogs are more anxious, energetic, or aggressive than others. Remarkably, several of the same genes linked ...

Despite the remarkable advancements in human psychiatry over recent decades, veterinary psychiatry remains an underdeveloped and loosely defined field. While it addresses psychological problems in ...