Sure your general personality plays a big role, but you can't deny that men and women are treated differently in society. You'd have to be insane and blind to think otherwise. As a natural consequence of this, men and women will also likely be treated slightly differently with regards to a stutter. Are girls more likely to be perceived as "cute" with a stutter due to women being expected to be "shy" or what-not in some situations? Or maybe a stutter will more greatly impact things like job interviews and such due to the already existing bias that some might have of women being "incapable". I can't say anything for certain, which is why I agree that there should be more studies done on this.