The Bobo doll experiment showed that kids can learn aggression by watching adults act aggressively. Boys acted more ...

Aggression can be contagious, suggests new research. People who repeatedly observe aggressive behavior have a higher likelihood of engaging in violent behavior themselves, scientists say. Researchers ...

Like humans, mice will compete over territory and mates, and show increased confidence in their fighting skills the more they win. At first, a brain chemical called dopamine is essential for young ...