Add Yahoo as a preferred source to see more of our stories on Google. How can parents distinguish typical aggressive behavior in kids from something more extreme? Experts explain. (Image: Getty; ...

Chimpanzees have a reputation for being aggressive, while bonobos are often seen as their peaceful counterparts. This ...

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.

Passive aggression, like most troubling aspects of behavior, occurs on a continuum. We have identified five distinct and increasingly pathological levels of passive-aggressive behavior that tend to ...

Research scientists say kids who are persistently aggressive or defiant in their teens were likely showing signs of persistent aggressive behavior years earlier when they are toddlers. Sometimes as a ...

Forbes contributors publish independent expert analyses and insights. Patricia writes about family law and tips for female lawyers. Aggression is defined as a form of physical or verbal behavior ...

Passive-aggressive people often say these 11 unnerving things without even realizing how damaging they sound. If you've ever ...

The stereotype of violent chimpanzees and peaceful bonobos may be wrong, according to new research comparing aggression in both apes.

A new study reveals that behavioral isolation between populations of Bahamas mosquitofish is driven primarily by the actions of females—not just through mating choice behaviors, but also through ...