try and do the sums as it were and think it through, and if you do that, i think you'll see that er, it does work out this way  and of course, it gets er, even worse if you consider questions like relatedness through parents, because clearly i may be related to my mother's sister's children, my cousins, er no it's actually nieces, because my mother and her sister share genes, but i'm not er necessarily related erm in the same way, erm, through er, my father's er relatives, for example , because although erm, because my er, my, my relationship between mother's kin and my father's kin is purely through marriage, so they have no joint genetic relatedness.