I find it interesting how focused this article is in the "traditional" male gender role. It doesn't even touch the subject of different friendship types and relations when involving other genders than 'male'.

Without denying that sex has it's toll in the physical (duh) and psychological treats of a person, I do believe that traditional gender roles are the only roles taken into account for this article, making a great deal of assumptions on how males act towards friendship. Does anyone know if there are studies such as the ones mentioned in the article that take into account a less black and white view of gender roles or that digs into other types of friendships?