The sports culture surrounding football and wrestling may be fueling aggressive and violent behavior not only among teen male players but also among their male friends and peers on and off the field, according to a Penn State study.

"Sports such as football, basketball, and baseball provide players with a certain status in society," said Derek Kreager, assistant professor of sociology in the Crime, Law, and Justice program. "But football and wrestling are associated with violent behavior because both sports involve some physical domination of the opponent, which is rewarded by the fans, coaches and other players."

Using a national database of 6397 male students from across 120 schools, Kreager analyzed the effects of team sports – football, basketball, and baseball – and individual sports – wrestling and tennis – on male interpersonal violence. The study looked at factors such as self-esteem, reports of prior fights, and popularity of the various sports.

The researcher found that, compared with non-athletes, football players and wrestlers face higher risks of getting into a serious fight by over 40 per cent. High-contact sports that are associated with aggression and masculinity increase the risk of violence, he concluded.

"Players are encouraged to be violent outside the sport because they are rewarded for being violent inside it," Kreager said.

However, the violent behavior is not restricted to players alone. The Penn State researcher also found that the risk of getting involved in fights increases with the proportion of friends who play football.

"Males with all-football friends are expected to have a 45 per cent probability of getting into a serious fight, more than 8 percentage points higher than similar individuals with no football friends and almost 20 percentage points higher than males with all-tennis friends," Kreager said in a recent issue of the journal American Sociological Review.

As for individual sports, wrestlers are 45 percent more likely to get into a fight than non-wrestlers, while tennis players are 35 per cent less likely to be involved in fights. The team sports, basketball and baseball, on the other hand, do not lead to fights.

The findings run contrary to a belief that participation in sports discourages anti-social behavior among boys because of the emphasis on teamwork, discipline and practice, and good sportsmanship and fair play.

"My results suggest that high-contact sports fail to protect males from interpersonal violence," Kreager said. "Players might be getting cues from parents, peers, coaches, and the local community, who support violence as a way of attaining 'battlefield' victories, becoming more popular, and asserting 'warrior' identities."

Pressure on teams to win games may be contributing to the problem, because it makes coaches want to build a stronger team by selecting aggressive players and encouraging a 'win at all costs' attitude both on and off the field.

A compromise solution, Kreager adds, is to break the cycle of aggression.

"There is definitely a gate-keeping role for the coach," he explained. "You would want to not select those kids you are already aware are uncontrollably aggressive, because they are going to be a problem for others in the team. And that is also going to encourage other kids who are hanging out with them to be violent."

The same also goes for players who start becoming more violent, Kreager added. "You want to sanction them somehow and make sure they are not rewarded, else other kids might get a wrong message and that might perpetuate the violence off the field."