MANY sporting teams have that player who suffers from white-line fever, that person that transforms from a mild-mannered accountant to someone who would take on 100 players if it meant winning the game.
While some sports are more physical than others and have a culture of aggressive behaviour James Cook University professor Joann Lukins said the onus is always on the individual player to control their actions and being the most aggressive player on the field isn't always a good thing.
Some sports are more suited to aggressive and assertive personalities but Dr Lukins, an associate professor of sport and exercise science, said regardless of the game being played those athletes who step outside the rules don't have enhanced personal performance or help the team's cause.
Dr Lukins, who also serves as sport psychologist with the North Queensland Cowboys, said she understands how a player's behaviour off the field has to be different to that on it to be successful in their chosen sport.
She said regardless of the level of competition, one of the keys to controlling behaviour is giving the players a defined set of instructions before each game.
"Players need to know what is required of them in their role (on the field) because it will be a little bit different to how they act on a day-to-day basis," Dr Lukins said.
"The challenge for athletes is to be assertive and keep their sense about them, to be able to make good decisions.
"We know when people are in a very violent frame of mind they are not thinking very clearly.
"It's not beneficial for an athlete to go out and be violent but it's beneficial for an athlete to be aggressive within the confines of the rules."
While there are some players who cross the line and lose control, others take some time before they explode.
Dr Lukins said many factors could contribute to a player losing control and becoming violent, including frustration at refereeing calls and retaliating to being hit.
But Dr Lukins said no matter what happened during the course of the game, the players are the ones who control what happens on the field.
"Ultimately I think the athlete has to take responsibility," she said.
"It's the athlete who makes the decisions to be violent, they have to take responsibility for that."
Many sporting codes have increased penalties for inappropriate on- and off-field incidences and there are fewer replays of altercations in televised games shown, something Dr Lukins said had impacted positively on reducing violence.
"I am pleased to see there is less violence on the sporting field when my kids are watching, I think that is a good thing," she said.