Epigenetically-effected sexual orientation
Support for a neurodevelopmental pathway comes from research investigating epigenetic dysregulation of sexual development in general, physical characteristics, and functional as well as structural brain differences in pedophilia.
…if specific genes or genomic regions are found to be primary determinants of sexual orientations, upstream and downstream genes are likely also to play crucial roles. And these multigene interrelationships will have profound impact upon phenotypes and judgments derived therefrom. Parenthetically it is interesting to note even the yeast Saccharomyces cerevisiae has a gene-based equivalent of sexual orientation (i.e., a-factor and alpha-factor physiologies). These differences arise from different epigenetic modifications of an otherwise identical MAT locus (Runge and Zakian, 1996; Wu and Haber, 1995).
Experimental evidence continues to show that the epigenetically altered microRNA/messenger RNA balance determined the cell types of all cells in all tissues in all individuals of all living genera. Sexologists have ignored virtually all that experimental evidence and continued to place their findings into the context of visual input and brain imaging.
Despite my award winning review, The Mind’s Eyes: Human pheromones, neuroscience, and male sexual preferences, and my 2007 Plenary session at the annual meeting of the Society for the Scientific Study of Sexuality, the impact of this large group of primarily “social scientists” has limited the impact of accurate information about the neurobiology and psychology that has steadily come forward from organizations like the RNA Society.
Eventually, all serious scientists will ask the social scientists, how could you ignore all the experimental evidence that links cell type differentiation to the molecular epigenetics of behavioral development, when only one amino acid substitution clearly affects the life history transitions from adolescence to adulthood?
My feeling is that the social brain has many levels. If you don’t understand the foundational level, then you can do brain imaging until you’re blue in the face, but you still will not understand the process at a deep causal level.