What is the basis for the Church’s teaching about gender theology?

The Church’s recent teachings on the subject of gender theology are grounded in moral and ethical positions that are based on outdated anthropological studies. Specifically, the hierarchical Church continues to hold firm to the belief that “sex” and “gender” are synonymous and that “natural law” dictates that the innate biological differences between male and female need to be adhered to. Furthermore, the Church points to the “complementary” relationship between man and woman and that both the institution of marriage (the Church equally opposes same sex marital unions) and procreation are threatened by gender transitioning (deemed a “choice”).