Let’s say a man marries a woman and they have a child Thomas. The woman dies and then the man marries the woman’s full blooded sister. Those two have a child Patrick.
What name is given to the relationship between Thomas and Patrick? They are certainly half brothers, yet they also share two sets of common grandparents which is exactly like full blooded brothers.
Three-quarter brothers? That also doesn’t seem right because their ancestral tree is identical throughout the ages (like full brothers) except for one single individual.
Not a single name that I know of. Via Dad, they’re half brothers (different mothers). The offspring of siblings are cousins, so along the maternal line(s), they’re first cousins.
Wife and I had this argument today. I say no. The offspring of siblings are cousins, but that assumes different father/mothers. The definition I have always heard is that cousins share a common set of grandparents. But it must mean ONLY one set or else all brothers would also be cousins.
IOW: “First cousins” doesn’t do it justice; they are closer than that. They are also closer than half brothers.
Thomas would be both Patrick’s half-brother and first cousin. I wonder if this was more prevalent in ye olden days, I imagine it would be common in cultures with polygamy.
His first wife and the child died during childbirth. He married his now deceased wife’s sister and had children. Suppose his first wife had a child with him prior to the unfortunate early death. The relationship between that child and his other children would be what we are discussing.
All I can say is that, if they were opposite sex, they definitely shouldn’t reproduce.
Anyway, half siblings, since they were never cousins before they were half siblings. Definitely not step siblings. I have a step mother and her son, my father’s son, is my half brother, not my step brother.
Even if the sisters were identical twins, nobody would call them both brothers and cousins. Isn’t this sort of an “a greater subsumes the lesser” status? They are not cousins because they have a closer relationship: that of half-brothers. Yet, their relationship is even closer than that.
ETA: As I think more, half-brothers and cousins are pretty much genetically the same. They share one common set of grandparents and the other set are strangers one to the other. This is more than that as they have two common sets of grandparents, but are not full brothers.
All brothers are, in fact, cousins. Zeroth cousins, if you want to be more precise about it.
And there’s also such a thing as double cousins, where a pair of siblings from one family marry respectively a pair of siblings from another family, and then have kids. Those kids definitely aren’t siblings, but still have all four grandparents in common.
Unless the father and sister immediately become estranged, they will grow up just like brothers, not like cousins, so I would say (again) that they are half-brothers.
I say no. The offspring of siblings are cousins, but that assumes different father/mothers. The definition I have always heard is that cousins share a common set of grandparents. But it must mean ONLY one set or else all brothers would also be cousins.