George Robinson Posted almost 2 years ago Strange questions that humans have not yet found an answer for! As stated before, the gender of a person is determined by chromosomes randomly before birth. This is the basis of biological gender, which gives people the usual feelings, desires, and attributes associated with their gender (males tend to be more aggressive because of higher levels of testosterone while women enjoy bonding with others more because of higher levels of a neurotransmitter known as oxytocin). So biology mostly determines the physical and mental attributes associated with gender. However, environment probably also plays a role. I think people's perception of their gender is modified by the way others see them, relating to the concept of "the looking glass self." Maybe for example, men who excel at sports and can easily attract females will see themselves as very masculine while more shy men might have a lesser feeling of being masculine, but this is only a slight modification of their actual gender. I don't think very many people can be convinced that they are of the opposite gender from their interactions with other people, it doesn't seem likely to me. Also, some people might have hormonal imbalances which cause them to act differently for their gender. I think gender is a conglomerate of multiple factors, but is mostly determined by genetics. But you never know!