In a review of more than 250 studies on sexual behavior in people under 25, researchers at the London School of Hygiene and Tropical Medicine discovered that it was social and cultural factors and not any sort of ignorance or unavailability that influenced the use of condoms by young people.

The 14-year study showed that young people assess a potential partner's disease risk, and the need for a condom, by their appearance and extent of social interaction.

Researchers found that some of the sexually active participants in the studies associated condoms with lack of trust while others believed that carrying them could imply sexual experience.

The data collected from countries including Britain, Australia, Mexico and South America, also revealed that women had more restrictions on their sexual freedom as compared to men. Men were expected to be highly sexually active and women were expected to be chaste.

Dr. Cicely Marston and Eleanor King reported in a study published in The Lancet medical journal,

"This study summarizes key qualitative findings that help in understanding young people's sexual behavior and why they might have unsafe sex," said.

Researchers said the findings help explain why many HIV programs remain ineffective, adding that such programs "merely provide information and condoms, without addressing the crucial social factors."