First year university students are likely to have more sex than their third year colleagues, a study indicates.

Researchers at the University of Central Lancashire in Preston studied the sex lives of students in the North of England.

They found that accommodation - as well as psychosocial factors such as beliefs and knowledge - played a great part in a young person's sexual habits.

Predictably, researchers found that a student living in the parental home was less likely to have many sexual encounters.

But the effect of living in a privately rented shared student house also acted as an inhibitor to sexual activities, researchers found.

Students who were the least inhibited and most sexually active were those living in halls of residence.

The researchers had predicted that students living away from the parental home for the first time, in student accommodation, might be more likely to engage in more sexual encounters and have more sexual partners.

They labelled this as a "situation-dependent disinhibitory effect."

Report author, Sylvia Smith, said that the predictions were confirmed.

She added that students as a group tended to expose themselves to high rates of sexually transmitted disease infection as a result of their risky sexual behaviour, and that the team's findings would have implications for the targeting of sexual health education.

Another piece of research, carried out at Staffordshire University in Stoke-on-Trent, revealed that only a third of undergraduate students thought that oral sex constituted "having had sex".

The findings are similar to those of a US study conducted last year.

Researchers say there were significant gender and age differences in responses.

The report concludes that any studies of sexual behaviour need to specify which behaviours are encompassed by the definition of "having had sex".