Coed school

Igros Moshe (Y.D. I #137): Question: Is it permitted for young boys and girls to be taught together? Answer Coeducation, for even the youngest children, is surely some­thing that would not please our Sages. While small children experience neither temptation nor lewd thoughts, we must still train them to distance themselves from women. Yet when they study together, they become accustomed to closeness. They will remain accustomed to this when they grow up, as well, when they do face temptation, and the danger of lewd thought. Therefore, although there is no risk of breaking any prohibition now, our educational duty still stands." I am willing to be lenient in an emergency, where an all-girl school cannot be formed, and the alternative is public school." which teaches neither faith nor good deeds. Better that very young children, regarding whom the prohibition does not apply, should be educated in schools founded by the God-fearing, even if boys and girls study together. It is clear and simple that if there is any chance of founding an all-girl school, it must be done. Of course, slightly older children are legally forbidden'" to study either religious or secular subjects in such a school.

Igros Moshe (YD II #104) Question: Is it permitted for young boys and girls to be taught together? Answer  You obviously don’t need me to answer this question but merely to reinforce your view since you say there is a dispute even from some religious Jews who don’t realize that there are concerns. Therefore I am writing that my view is this is prohibited and I have previously ruled that this is from the age of six in some places  However there are those who claim that there is no problem because there is no lust for the opposite sex at this age. Nevertheless there is an obligation of chinuch which means to accustom them to behave now in staying away from the opposite sex because they will need to do it later. However when they learn together as children they become accustomed to be with the opposite sex so that this will continue even when they are older when they will have lust for the opposite sex. So even though there is no problem of prohibited sin now when they are little children but there is a an obligation of chinuch.  There in fact is a dispute about the nature of chinuch whether the behavior needs to be exactly the way it will be when they grow up or only similar. So those who are lenient say that since young children don’t have lust there is not even a mitzva of chinuch. However I hold that it is prohibited to teach boys and girls together even when very young. In America there is a question of what age is considered a child.  Some want to say this means even at the age of 9 or 10 they are still children. While it is clear that even young boys and girls should not be taught together, there are some places that I have agreed that they can be lenient and have coed classes . That is because it is impossible to have a separate school for boys and girls and that would result in the children going to public school. Therefore it is obviously better that they learn in a religious school even if the classes are coed for young children.