The concept of gender has three faces. Natural gender (N-gender, or sex), Social gender (S-gender), which reflects the social implications of being a man or a woman (or perhaps something in between), and Linguistic gender (L-gender). L-gender tends to mirror social and cultural stereotypes of S-gender. Recurrent correlations between shape, size, and L-gender choice are a feature of languages of the Sepik region of Papua New Guinea. After a brief summary of L-gender and the principles of its choice across languages, a detailed analysis is offered of L-gender choice in Manambu, a Ndu language from the Sepik region. It is shown that gender assignment to humans correlates with N-gender and reflects S-gender status. Other nouns have no fixed gender. Their gender depends on the physical properties of the noun’s referent. We then turn to a cross-linguistic survey of other languages, in New Guinea and beyond, where shape and size are deployed as semantic parameters in L-gender choice. Further semantic correlates of gender assignment in the languages of the world include the roles of referents in myths, and salient properties correlating with the position of S-gender (especially relevant for L-gender choice and L-genders switches for humans).