I suppose the most important thing, the heaviest single factor in one's life, is whether one's born male or female. In most societies it determines one's expectations, activities, outlook, ethics, manners - almost everything. Vocabulary. Semiotic usages. Clothing. Even food. Women... women tend to eat less... It's extremely hard to separate the innate differences from the learned ones. Even where women participate equally with men in the society, they still after all do all the childbearing, and so most of the child-rearing.