Yes, that the married state is a boolean, is not immediately clear. However, I don't think that's why people don't consider the tree. For example, pose the same

Yes, that the married state is a boolean, is not immediately clear. However, I don't think that's why people don't consider the tree. For example, pose the same question in the form male/female. 1. Jack is looking at Anne, but Anne is looking at Eve. Jack is male, and Eve is female. Is a male looking at a female? Although this question might even be less "boolean" than the married/unmarried one, my hypothesis is that more people will say A. And, just a nice coincidence that my name happens to be Anne. :-)