The across-species genetic conservation of intercellular and extracellular chemical communication enables unicellular and multicellular organisms to functionally distinguish between self and non-self. Non-self olfactory/pheromonal input from the social environment elicits a vertebrate neuroendocrine response. The organization and activation of this neuroendocrine response modulates the concurrent maturation of the mammalian neuroendocrine system, the reproductive system, and the central nervous system during the development of sexual preferences that may be expressed in sexual behavior. Psychophysiological mechanisms for the development of these sexual preferences include focus on unconscious affects that are detailed in reciprocal cause and effect relationships. Olfactory/pheromonal conditioning elicits neuroendocrine effects accompanied by unconscious affects on the development of sexual preferences. Integrating these unconscious affects extends to humans a developmental model of behavior that includes the development of male sexual preferences for other malesHow much of sexual orientation - and crystallisation of gender identity - is tied up with, of all things, our sense of smell? How does our olefactory environment affect the plastic regions of the brain?
OK, there's some things about this very dense and difficult to read paper that make it less useful than it could be. It's all about sex. It's all about males. It's all about gay males. The female of the species is not considered, neither are issues of sex identity. There's also this:
Rarely do sex researchers address the ongoing philosophical debate between canonical neo-Darwinism and Biblical creation. Perhaps this is because any debate between scientific theory and religion arises from distinctly different domains of cognitive thought. Does the acceptance of Darwin’s theory represent the glorification of Science pitted against religion, or is it a means by which Science and religion might be integrated? Integration of Science and religion might be achieved by recognizing that the key components of this olfactory/pheromonal model appear to be as irreducibly complex as the basic tenets of evolution and the basic tenets of religion.Um. If you say so.
Never mind, worth adding to the references, because sense of smell is something intimately connected to the parts of the lymbic nucleus that deal with sex identity (yes, gender identity is the usual term, mine's more accurate though). And we know it's affected by hormone levels, and transsexuals show cross-sexed neuroanatomy here. So a part of the puzzle.
See also Will gender exist 100 years from now, or does it already not exist?