I believe the answer is: castration anxiety; penis envy
According to Freud, Every children has unconscious desire to attract the figure that has the opposite with them, and often reflected in the desire to attract mothers' attention in boys and attract father's attention in girls, this concept is called oedipus complex.
The masculine physical trait often seen as positive traits among the two because it makes them think that they could be the aggressor in the formation of relationship.