Claims that children need both a mother and father presume that women and men parent differently in ways crucial to development but generally rely on studies that conflate gender with other family structure variables. We analyze findings from studies with designs that mitigate these problems by comparing 2-parent families with same or different sex coparents and single-mother with single-father families. Strengths typically associated with married mother-father families appear to the same extent in families with 2 mothers and potentially in those with 2 fathers. Average differences favor women over men, but parenting skills are not dichotomous or exclusive. The gender of parents correlates in novel ways with parent-child relationships but has minor significance for children's psychological adjustment and social success.