Excerpt: 'You Were Always Mom's Favorite!'

Sept. 9, 2009— -- In her new book, "You Were Always Mom's Favorite!," Deborah Tannen explores the powerful relationships between sisters, and the underlying forces of closeness and competition that complicate that special bond from childhood into adult life.

Read an excerpt of the book below.

"I love her to death. I can't imagine life without her," a woman says of her sister. Another says of hers, "I want to be around her all the time. She's the only one who knows all kinds of stuff from the past. All we have to do is say one word, and we know when the other one will start laughing." I heard many comments like these from women who told me that their relationships with their sisters are among the most precious aspects of their lives.

I also heard comments like this one: "I don't want anyone to kill my sister because I want to have the privilege of doing that myself."

Though they sound so different, these remarks have something in common: the intensity of feelings behind them. Sister relationships are among the most passionate of our lives. One woman explained, "My relationship with my sister is more deeply emotional than any other." Yet another, after telling me ways her sister had hurt her -- tales of betrayal that made me wonder why she still talks to the perpetrator at all -- said, "No matter how difficult my sister is, she is still part of me, part of my past, my present, and my future." Then she added, echoing the comment I quoted at the start: "Love her or hate her, I can't imagine life without her."

Conversations with sisters can spark extremes of anger or extremes of love. Everything said between sisters carries meaning not only from what was just said but from all the conversations that came before -- and "before" can span a lifetime. The layers of meaning combine profound connection with equally profound competition. Both the competition and the connection are complicated by inevitable comparison with someone whose life has been so similar to yours and yet so different-- and always in your view.

I was chatting with four women at a party. As we talked, we gradually sat down, then drew our chairs into a circle. The other party guests looked on with curiosity or envy as our tight little group erupted in laughter or rippled with a wave of knowing nods. I had brought up the topic of sisters. Laxmi, a woman visiting from India, was extolling hers. "When we meet we can't get enough of each other," she said. "When we ride in a car together, my husband threatens, 'I'm taking another car! You two never stop talking and laughing!' She's my lifeline. I'm her lifeline. If I say one word, she knows what I'm going to say. We've made a pact that we'll take a vacation together at least once a year." Another woman in our group remarked sadly, "That's why I always wished I had a sister." I wanted to learn more about this wonderful sister relationship, so before the party ended I arranged to interview Laxmi one on one.