The largest umbrella organisation for modern Orthodox high schools in Israel has recommended that its affiliated institutions start teaching sex education.

Until now, sex education has been absent from yeshivah high schools, modern Orthodox boys’ schools which place a heavy emphasis on religious studies. However, Bnei Akiva Yeshivot, which have 27 affiliated boys’ schools across the country, this week told teachers that it is time for change.

In recent months it has been encouraging its 24 affiliated girls’ schools to introduce sex education.

Rabbi Yehuda Felix, the organisation’s educational director, said that the move stems from recognition that students need to know about adolescence. “Young people today must know about this dull period that starts at 12 and goes on, according to some opinions, until 35 or 40,” he said.

His recommendation to yeshivot coincided with the launch, on Monday, of a new programme to help teachers in religious schools teach sex education. It was prepared, at Rabbi Felix’s request, by the Ramot Shapira Seminary near Jerusalem and its family education centre, the Lieberman Institute.

Malchi Cohen, head of the Lieberman Institute, said that the course marks a sea change in religious schools’ attitudes towards sex. Until now, when sex has been raised in the classroom, it has been in the context of understanding laws or preparing for married life. But, says Ms Cohen, “the message that if they get married everything will be ok is not correct”.

In the new course, teachers “give information and tools for students to understand their bodies now and not just when they are 25”.

Students will learn about biological changes in their bodies, anatomy of the opposite gender, sexual desire, homosexuality, and in those schools that are prepared to teach it, contraception.

Each subject is taught from a scientific perspective and a religious perspective, and teachers are encouraged to speak about tensions students will feel between sexual desire and religious law. According to Ramot Shapira Seminary director Zeev Bar-Lev, who authored components that are specific to boys’ schools, the course partly sets out to address a problem “that happens all the time” of students dropping out of prayer services or religious study because they feel guilty if they have masturbated or had a wet dream.

“They feel tameh,” he said, using the Hebrew word for ritual impurity.

“We try to tell them that if someone woke up in the morning and felt that something happened last night it’s not because he is crazy or it’s unnatural or there’s something wrong with him,” said Mr Bar-Lev.

Teachers are told to stress religious prohibitions but at the same time be “non-judgmental” and stress that nothing casts students outside the community.

He said that the same is true in discussions about homosexuality.

As well as helping students to get through adolescence, the programme is also meant to help them when they enter a relationship or marriage.

It teaches boys how to be sensitive to women. For girls, it confronts a problem stemming from the fact that the first formal education about sex they get is in their bridal classes.

Ms Cohen said: “Every bridal-class teacher I speak to says they find it difficult to convince women that what has until now been immodest is now special and holy.”

Despite enthusiasm for the course in the Bnei Akiva schools, some observers of the religious community are sceptical about what it will achieve.

Avishai Ben Haim, religious affairs reporter for the Israeli daily Maariv, said that given there is no flexibility for permitting any pre-marital sexual acts, the rabbis “cannot deal” with the sexual angst and frustrations of religious teenagers “because there’s no solution”.