Announcement

Ascendants and descendants in the direct line — father and daughter, grandfather and granddaughter, and so forth — may not marry each other. Collaterals are prohibited from intermarrying if either of them is related to their common ancestor in the first degree of descent. Thus a man may not marry his sister, half-sister, niece or grand-niece.

I know you’ve got a hot date tomorrow night. Do you have a pre-exisiting personal relationship? Are you related? Is it your brother’s wife’s cousin?

Experts answer what they know. The Non-Expert answers anything. We answer by way of flowchart. Have a question? Need some advice? Ignored by everyone else? Send us your questions via email.