Toronto, March 19 (IANS) Factors such as gender, sexual orientation and the desire to form lasting romantic relationships appear to influence sexual risk-taking among young adults, a new study suggests.

The study, published in the Journal of Sex Research, categorised people into three groups -- heterosexual men, heterosexual women, and homosexual men -- and found that all three had a preference for different condom negotiation strategies.

Heterosexual men tended to choose more passive strategies (and were most likely to agree to sex without a condom); heterosexual women tended to choose more assertive strategies (like withholding sex).

Homosexual men tended to aim for a balance, choosing more verbal strategies than heterosexual men, but selecting strategies that were not confrontational.

The findings also explain some of the motives and reasoning that influence risky behaviours. For example, the study found that heterosexual women were more willing to take risks when the couple has a stronger relationship motivation.

"It is particularly striking that women had lower expectations that their partner would be interested in condom use - this highlights how challenging heterosexual women expect the negotiation of condom use to be," said lead author Shayna Skakoon-Sparling from the University of Guelph, Canada.

For the study, the team involved 157 heterosexual men, 177 heterosexual women, and 106 homosexual men, aged between 18-25 years.

Participants were presented with a vignette describing an encounter with a hypothetical new sexual or romantic partner and were asked to rate their attitudes and likelihood of choosing particular courses of action, as well as their relationship motivation.

The findings may help explain why some young people engage in unsafe sex even though they are aware of the risk for sexually transmitted infections (STIs), HIV, cervical cancer and unplanned pregnancy.