You can usually tell which one is the pitcher and which one is the catcher.
Strong families are based upon either biological ties, or upon what can be plausibly regarded as biological ties; any decently-bred person has one each mother, father, maternal grandmother, maternal grandfater, paternal grandmother, and paternal grandfather; whether these persons are blood or adoptive relatives, and whether they're living or dead, they're all distinct individuals. When a couple gets married, they're establishing the identity of the six afforementioned relations for any children of theirs who will come into the marriage whether by birth or adoption.
Although the alarming divorce rate in this country means that many children don't get raised by both parents, at least both parents will exist as identifiable individuals. How would one draw the family try of someone who was adopted from birth by a couple of men or a couple of women?
He speaks for most of us.