WASHINGTON (AFP) ― Youths who play video games are more likely to think and act in aggressive ways, suggested a study out Monday of more than 3,000 schoolchildren in Singapore.

The research, published in JAMA Pediatrics, a journal of the American Medical Association, was based on more than 3,034 children who were studied over the course of three years.

Frequent use of video games was linked to higher rates of aggressive behaviors and thoughts, according to self-reported answers to survey questions by the children.

The participants’ average age was 11 at the start of the study, and three-quarters of them were boys.

The study also found that answers were similar among boys and girls, and that parental involvement was not likely to change behavior.

The researchers said their findings support previous research that has shown a link between video games and aggression.

“This study found that habitual violent video game playing increases long-term aggressive behavior by producing general changes in aggressive cognition, and this occurs regardless of sex, age, initial aggressiveness or parental involvement,” said the study which was led by researchers at the National Institute of Education in Singapore and the Iowa State University department of psychology.

Participants were asked to respond to six questions about aggressive behavior, such as, “When someone has angered or provoked me in some way, I have reacted by hitting that person.” Responses were given on a scale of one to four, ranging from “strongly disagree” to “strongly agree.”

Three questions on hostile thoughts were included, such as, “Suppose a boy says something bad to another boy John. Is it wrong for John to hit him?”

Answers were also given on a four-point scale, from “really wrong” to “perfectly OK.”

Outside experts questioned the methodology of using self-reported answers rather than measuring behavior itself, and said the study does not prove that violent video games caused aggressive behavior in the youths.