Young men like Alonzo, who practices abstinence, wonder if they are in the minority. "Maybe it is appropriate to say that I am one of those vanishing or endangered species of persons who are committed to preserving the value of conservativeness; the value of the sacredness of sex," says the 20-year-old from the Philippines.

Both Melissa and Alonzo are doing their best to cope as sexual beings. They know that adolescence often means shame and pregnancy for girls, while boys are expected to focus on prowess and pride in proving manhood.

Boys are most often raised with different ideas and expectations than girls. That is not news to Carolina, 18, who dislikes the different treatment but worries that boys need more guidance then they receive.

"Boys can come home late, while girls can’t go out at night. Boys can go out without saying where they are going, while girls must undergo a big cross-examination before they go out. Not everything is bad for girls, however. So much freedom (for boys) can take them into the world of drug addiction, expose them to venereal diseases and many other things."

Her worries are well-founded: in the United States, while fewer than one in three girls discuss reproduction, sexuality and family planning with either parent, the number of boys who do so is only one in six.

Monica, 16, says the lack of guidance is similar in her country, Peru. "Mothers are shocked when their daughters or sons ask them questions about sexuality. And I say ‘mothers’ because the majority of fathers never touch upon this subject with their sons, encouraged by the male chauvinistic belief that it is the mother’s job to look after the children while they themselves only have to bring home the money."

Jean Marie, 23, who sees the impact of HIV/ AIDS in Uganda, believes that girls who are taught about human sexuality by their aunts are luckier than boys left to learn from experience. Honest communication is hard to find for many boys, who play out social stereotypes to feel more like grown men and sometimes face harsh consequences.

Boys get the idea that raising children is a "female thing", not much to do with males. Focusing on the relationship between fathers and children can encourage young men to be involved in family life. Likewise, understanding the situations and pressures faced by boys and young men can make education and health services more responsive and effective.

Folade, a 20-year-old from Nigeria, says a family life education programme taught him a lot about life: "Even boys can now understand why a girl has to say ‘no’.... I have learned so many things I didn’t pay attention to in my biology class."

For their part, young men must take equal responsibility for safe and healthy sexual behaviour. This includes respecting the reproductive choices of young women, using contraceptives and accepting responsibility in case there is a child. There is a long way to go before many men take on this level of responsibility and accept the need for change. When society says it is time to do so, the changes will have an undeniably positive impact. More support from young men will lead, in time, to healthier and more prosperous families and better opportunities for young women