I remember asking this a long, long time ago but I don’t remember the answer. This is one of those things that I have to have drilled into me before it sticks.
What’s the difference between a second cousin (or third cousin) and a cousin once (or twice) removed?
You see, I’ve got these cousins who always called me Titi (Auntie). They are the children of my aunt. These cousins now have children (they also call me Titi but that really doesn’t have anything to do with anything, does it?).
My aunt’s children are my cousins. My cousins children are my, um, second cousins? How do I get them “removed”?
I forgot to address the second cousin part. Your first cousins once removed are your children’s (if you have 'em) second cousins. You share grandparents with a first cousin. You share GREAT grandparents with a second cousin.
The children of your first cousins, are your first cousins, once removed.
The grandchildren of your first cousins, are your first cousins, twice removed.
Your children, and your first cousins’ children, are second cousins to each other.
The way I remember it may be useful (or not). It’s all about grandparents. First cousins have the same grandparents. Second cousins have the same great grandparents. Third cousins have the same great-great grandparents and so on. If my grandparents are your great grandparents then we are first cousins once removed. If my great grand parents are your great-great grandparents, then we are second cousins once removed. It’s easy if you just think about grandparents as the linking factor.
daffyduck, the problem with that explanation is that, while, say, third cousins have the same great-great-grandparents, so do second cousins and first cousins and siblings.
You would have to emphasize that the nearest ancestors that third cousins have in common are great-great-grandparents.