EW: Many women have really dear friends who they consider to be like sisters—they call them sister-friends or sister substitutes. Can those relationships ever really be the same as the relationship you have with a sibling?
DT: No, of course it never is. When women told me they have friends who are like sisters or they chose their sisters, they usually have in mind the positive sides of sisterhood, not the negative. They weren't looking to have a friend who knew exactly how to get your goat! Or a friend who, if you get too far ahead, she's going to want to pull you down—not that all sisters do that, but this can be a side of it. Clearly they don't have the memory of your childhood, the complete understanding of what it was like to grow up in the house you grew up in.
EW: There can be extreme drama between sisters. Extreme anger, extreme love—why is there often so much extreme behavior between sisters?
DT: There can be because you feel so strongly about each other. Another example I like is, a woman I interviewed told me she and her sister talked on the phone and sometimes they ran out of things to say, but they didn't want to get off the phone so they just left the phones off the hook, so they were still keeping each other company even though they had nothing more to say. She said, "It is just comforting to know she there, like hugging a cat." I loved that, and I decided I would use that [in the book] to show how special and wonderful sisters can be. Then, the next time I saw this woman I said, "How's your sister?" and she said, "I don't know, I'm not talking to her!" They didn't talk for a year!
Before the book went to press, she said they were talking again, and again they were taking the phones off the hook. I think it captures [that idea] that because you care about each other so much and you care that much about each other's opinion, it means you can be deeply hurt as well as deeply comforted.
EW: How have women reacted to your book so far?
DT: One of the responses I get, that I appreciate, is, "It is so good to know that I'm not the only one." Because there is so much idealization of sisters out there that the word "sisterhood" in of itself means a perfect relationship. I think it is important to remember that there are so many different ways to be sisters.