Linguist Deborah Tannen comments on research indicating that sisters provide more emotional support than brothers: "I interviewed more than 100 women about their sisters, but if they also had brothers, I asked them to compare. Most said they talked to their sisters more often, at greater length and, yes, about more personal topics. This often meant that they felt closer to their sisters, but not always. One woman, for example, says she talks for hours by phone to her two brothers as well as her two sisters. But the topics differ. She talks to her sisters about their personal lives; with her brothers she discusses history, geography and books. And, she added, one brother calls her at 5 a.m. as a prank."