It doesn't turn the group masculine, it turns the word used to the masculine plural, which is the generic word for a group of people. But if you take sciences,

It doesn't turn the group masculine, it turns the word used to the masculine plural, which is the generic word for a group of people. But if you take sciences, for example, it's plural feminine in French and Italian. If you put a masculine discipline in the group, for example "law" which is masculine in Italian (il diritto), the group of disciplines is still referred to as feminine "le scienze" It's a matter of gender of the plural word, it has nothing to do with biological sex.