"Fathers' involvement [with their children] seems to be linked to improved verbal and problem-solving skills and higher academic achievement. Several studies found that the presence of the father is one of the determinants of girls' proficiency in mathematics. And one pioneering study showed that along with paternal strictness, the amount of time fathers spent reading with them was a strong predictor of their daughters' verbal ability. For sons the results have been equally striking. Studies uncovered a strong relationship between fathers' involvement and the mathematical abilities of their sons. Other studies found a relationship between paternal nurturing and boys' verbal intelligence." —David Popenoe