Chivalrous acts are meant to prove that a man has certain good middos that we wouldn’t necessary expect; they aren’t natural.
zogt_besser: It is both silly and incorrect to assert that men are generally more middos-challenged than women and thus need to prove their good middos more than women.
In any event, your equation of middos with chivalry is contrary to the first definition given by Oxford as well as its listed etymology, which attaches religious significance (i.e. Christian) to it. Why do you also think the term is directly associated with knights (rather than the general public) who were Middle Ages warriors in Christian countries, at a time when warriors fought under the crosses flag?