Men are men and women are women: True or false? Gender is not always black and white. Genetics, medical conditions and other factors influence our sexual identity. Males and females are better considered along a male-female continuum rather than as opposite ends of a complete dichotomy. So argued my PhD supervisor’s supervisor, Dr. John Pinel from UBC. There is substantial biological reasoning for this viewpoint. First, consider genetics. We categorize sex according to the chromosomes X and Y. As their 46th chromosome males have an X and a Y and females have two Xs. Mothers pass on their X chromosomes to offspring, because they only have Xs, whereas fathers pass on both their X and Y. When they combine during fertilization, they give rise to either a male (XY) or female (XX). During normal development, the body produces the sex-specific hormones testosterone and estrogen and they circulate through the body to