Final answer:
Aggression is defined as the intentional infliction of physical or psychological harm on another person, encompassing both hostile and instrumental forms. Bullying and cyberbullying are examples of aggression, which can have various functions and motivations.
Step-by-step explanation:
Of the following choices, the best definition of aggression is intentionally inflicting physical or psychological harm on another. Aggression is a behavior that encompasses the intention to cause harm or pain, whether it is physical, psychological, emotional, or social. The concept of aggression includes both hostile aggression, which is driven by anger with the intent to cause pain, and instrumental aggression, where the goal is to achieve an objective rather than necessarily to cause pain.
Real-world examples of aggression include the physical fights between male gorillas using their canine teeth to cause wounds, and bullying, which may involve repeated behaviors intended to inflict harm on a victim and can manifest as physical, psychological, emotional, or social abuse, both in the real world and through cyberbullying.
Aggression can serve different functions such as displaying dominance, responding to threats, or achieving goals, and it can also be a consequence of cultural pressures in societies where aggression is seen as praiseworthy.