From Wikipedia: Fafafini (Samoan - Fa'afafine) is a third gender specific to Samoan culture. Fafafini are biologically men who have been raised to assume female gender roles since early childhood.
The Samoans’ gender roles are shaped by society. Men handle the heavy labor and the women take care of the domestic affairs, like cooking and cleaning. The use of Fafafini originated due to a lack of women to perform domestic tasks, combined with an overabundance of work. Being raised as a female, the Fafafini do not object to the female tasks.
In Samoan culture there is an emphasis on the group and family than on the individual. Therefore, whatever is best for the group is best for the individual. So raising a boy to be a woman is not taboo because they have been given a role in society as a third gender. Even so, some boys don’t submit to being a fafafini.
Fafafini think of themselves as better than men and women at domestic skills. Because they have the body of a man, their extra muscles offer extra power to do chores.
They also don’t consider being a fafafini the same as being a homosexual or a drag queen. A fafafini won’t have sex with another fafafini, only straight men. They are physically men, but they are accepted as women because they look and act like women so when they have sex with men, it’s not considered homosexual. Usually a young Samoan man’s first sexual experience is with a fafafini.