I wonder why some languages have gendered nouns and others do not. And, of those that do, some have the Neutral grammar gender (German) and others only have male/female genders (French).

I have always wondered why and wanted to know if people who are native speakers of languages with gendered nouns differ in their mentality, if at all, from the native speakers of languages without gendered nouns (English). Whether the concept of gender as a social construct is impacted by the language. Also, just to denote that not all languages have a need for a new pronoun - the word for "his" and "her" is already the same in some languages. It seems that a lot of importance is placed on the use of language, so I wonder what has been studied already.