New York, May 13 (IANS): Heated political discourse over proposed laws involving marginalised groups, such as lesbian, gay, bisexual and transgender (LGBT) people, can contribute to an increase in bullying linked to students' identity in schools, says a study.

"We think young people do not hear what adults and lawmakers are talking about, but they do," said senior study author Stephen Russell from the University of Texas at Austin, the US.

In the run-up to a statewide voter referendum to ban gay marriage in California, young people reported significantly more homophobic bullying, showed the findings published in the journal Pediatrics.

In fact, homophobic bullying peaked and declined after the public debate about the initiative in question, Proposition 8, subsided.

The study looked at yearly survey data from nearly 5 million middle and high school students in over 5,000 schools in California, from 2001 to 2015, and whether those students experienced homophobic bullying.

The rate of homophobic bullying of students increased from 7.6 per cent in the 2001-02 school year to 10.8 per cent in the 2008-09 school year when the Proposition 8 vote took place.

This occurred even as trends in other types of bullying related to race or ethnicity, religion and gender declined, the study said.

"The data are telling us that straight kids are getting bullied for this, too," Russell said and added, "It's all about what the bullies perceive."