Playing violent video games, such as those depicting decapitation, could lead young people here to think and act more aggressively, said a study published on Monday.
The study of 3,034 primary and secondary school students here showed that those who played more violent video games tend to be more likely over time to commit acts of physical aggression, such as hitting someone who had angered them.
The Singapore study was one of the few here on the effects of violent games that featured a relatively big group of respondents and was done over a relatively long period of time.
Boys make up seven in 10 of those surveyed in the three-year study, started in 2007 by researchers from schools including the National Institute of Education (NIE).
Aggressive behaviour was found to be a result of students thinking aggressively, which was linked to playing violent games such as those with scenes of dismemberment or graphic killing.
The thoughts include fantasising about hitting someone they did not like, thinking someone who bumped into them by accident was hostile, and believing it was all right for others to hit people who provoked them.
The results were similar regardless of the students' gender, history of aggression and whether or not their parents restrict how long they play video games.
"What you put in your brain can translate into action. Aggressive thinking can lead to aggressive actions," said Associate Professor Angeline Khoo, one of the study's researchers from NIE.
By the same token, games that depict acts that benefit others can result in helpful behaviour in real life, too, she added.
She did the research with former NIE researcher Li Dongdong and media violence expert Distinguished Professor Craig Anderson of Iowa State University in the United States, among others. The study was published in the Journal of the American Medical Association Pediatrics in the US.
Commenting on the study, cyber-wellness experts cautioned that aggressive behaviour could be caused by other factors too.
Mr Nicholas Khoo, co-founder of Singapore's Cybersports and Online Gaming Association, which also promotes cyber-wellness, said focusing only on violent games might mean "we have missed out other possible root causes" for such behaviour.
Mr Khoo said these could include poor relationships with family and friends, which might lead youth to retreat into games. Playing violent games might be a sign of deeper issues, he added.
Mr Chong Ee Jay, assistant manager at Touch Cyber Wellness, was not surprised by the study findings.
Last year, the centre saw a high incidence of aggressive behaviour among cases involving excessive computer gaming.
He advised parents to keep abreast of the development and influences of media and technology on their children so they can adjust their parenting styles and set appropriate rules.
Parents should also be conscious of their own behaviour, said Mr Chong. "If they, too, use aggression to deal with their children, it will reinforce that inappropriate behaviour," he said.
"(Parents) also need to keep in touch with what their children are doing on the computer and the Internet," he added.