Innate learning such as the life and death instinct are potential causes of aggression within people, yet there is research proof that aggression can be learned through experience and exposure, through such things as television and violence in the family. .
Aggression is varied in different sports and in different people, based on social norms, sport norms and gender. Research suggests that males are more aggressive, but since aggression is based largely on correlation and circumstance, there is no way to define a gender trait. Frustration is one of the major causes of aggression and anger in humans, which can be applied to virtually all instances where aggressive behaviour is present. The presence of aggression in sports is a powerful force of motivation and action to many participants. This form of aggression is a positive factor, however it is when this behaviour turns to violence that there may be problem.
Road rage provides an example of aggression resulting from frustration and anonymity. "Since 1970, the mileage driven on U.S. roads has grown four times as fast as the population and eighteen times as fast as new roads." The research of Brian Parkinson in the journal "Anger on and off the Road" provides information relating the presence and level of anger prior to aggressive outbursts in driving situations. Three key factors theoretically effect the development of anger: the appraisal of anger, the communicative factors and the potential role of causation. This theory indicates that the mutual indifference and anonymity between drivers on the road better allows for the projection of blame onto others. .
Opposed to the directness and "availability" of everyday anger, driving scenarios dictate communication difficulties, specifically the unavailability of diffusion of the situation through discussion or acknowledgement of blame, two actions that often prevent further or physical retaliation.
