"What we found is there is an association, so that young people who watch porn are also more likely to engage in certain behaviours," Dr Lim said.
"Young people who are more interested in a variety of different sexual things, a bit more sexually developed, are the ones who watch porn more."
"The people who watch porn are the same people who don't use a condom."
The survey found Australians who viewed adult material at a younger age have a significantly earlier sexual debut, with a median age of 16 years.
More than 70 per cent of surveyed Australians aged between 15 and 29 indicated that they viewed pornography, with 14 being the median age of first viewing pornography.
An associated study found that there is an alarming disconnect between teenagers' perceptions of sexting and the actions they take.
While 77 per cent of respondents agreed that "It should be illegal to pass on a sext without permission", a third said that they "might show a sext" they received to friends.
Dr Lim said a higher percentage of homosexual Australians regularly watched porn compared with heterosexuals.
- AAP