The Economic and Social Research Council study shows that boys aged 13 to 14 also show a worrying tendency to blame the victim of violence. It said schools must reverse disturbing attitudes to violence among teenage boys.
The study - the first to focus exclusively on youth attitudes to violence - was based on evidence collected by researchers from Bristol, Durham, North London and arwick universities.
Dr Gill Hague, a domestic violence expert at Bristol, said: "I would not like to say that as boys get to be 13 to 15, they get more tolerant of domestic violence. But they become less clear about whose fault it is. This is disturbing because such attitudes may well continue as they get older."
More than 1,300 young people aged eight to 16 took part in the study. Dr Hague called on the Government to issue clearer guidance to schools, who had been slow in addressing the issue.