Physical Gender
To discuss this aspect of gender we need to examine hormonal involvement, in particular testosterone. During foetal life, the amount present, or the absence of testosterone and other androgens determines our sexuality — physically, mentally and emotionally. There are key times or periods during development when the foetus will go towards the male or the female depending on the level of testosterone. These windows of opportunity may be only open for a few days and if the needed level of testosterone is not present, a basic female orientation develops regardless of the testosterone levels before or after this critical period, and the resulting sexual imprint.