One of the more contentious issues in Western society is the relationship between biological factors, such as the presence of particular chromosomes at birth, and the gender a person identifies with. Or to put it more bluntly, if a person is born male or female, should society support that person identifying as a different gender, or transitioning genders?

The question this issue rests upon is how much weighting we give to biology, compared to the lived experience of the person. There is little doubt that people born biologically male tend to embody more masculinity, while those born female tend to exhibit more femininity.

Unpacking the cause of this is not something that is easy to answer. Just because two things tend to occur together does not mean one causes another. The classic example is observing that increased ice cream sales are associated with increased sunscreen sales. It would be wrong to conclude that buying ice cream causes people to buy sunscreen, instead warmer weather is the more likely underlying cause for increased ice cream and sunscreen sales.

So, can we say with certainty that biology determines gender identity? Is biology the cause, or just one contributing factor?

It seems evident that masculinity and femininity are not strictly tied to biological sex. A person can possess a high degree of either masculinity or femininity, irrespective of their biological gender. Most people have encountered someone who was born biologically male and brought a lot of feminine qualities, and vice versa. Not only that, these qualities can be developed irrespective of the biological gender of the person.

For this reason, I do not believe that we can conclude that biology is destiny. To quote Carl Jung:

"Humankind is masculine and feminine, not just man or woman. You can hardly say of your soul what sex it is". (Jung, The Red Book: A Reader’s Edition, p. 227)

It is interesting that this issue is often passionately pursued by religious adherents, when all of the major religions of the modern world says that our physical bodies are temporary. People seem to place so much attention on what they can directly perceive, even if it may not be of the greatest importance.