I know that English doesn't have specific gender for words like 'cousin' compared to other languages. While some languages seem to have a gender neutral form of he/she, are there some that only have one gender neutral word like 'sibling,' or 'child' and no difference between brother/sister, son/daughter, or niece/nephew?
My guess is that such a language would be one where all or most of its speakers know each other personally, and therefore have less need to identify each other by gender (or even by relatedness). It seems to follow that it would be a very small linguistic community, and hence almost all of its members would, to varying degrees, be blood relations. As I say, this is just my guess: it will be interesting to see whether my assumptions are borne out by the data.– Erik KowalJan 7, 2015 at 21:35
Depending on how much stock you put in the words and findings of Daniel Everett, the Pirahā language of Brazil is said to have only one word, baíxi (pronounced [màíʔì]) to mean both ‘mother’ and ‘father’, as well as one word for ‘sibling’—and no other kinship terms at all.