That was an interesting article. One thing I wondered after reading the article is what effect knowing you are related when you meet has. There was one example where the siblings did not know they were siblings, but most of the others occur after meetings. Of course, that data is probably much more available, so it is probably not possible to conclude one way or the other about the effect of knowing you are related.

It also seemed like the article was pointing towards, but never quite reaching the idea that many of the problems described are due to the fact that we (as a modern society? as a species?) do not know how to express non-sexual intimacy very well, especially between adults.