ENTWINED LIVES

A comprehensive survey of twin research that includes an impressive array of twin-related data in an anecdote-filled and entertaining presentation. Segal, a twin herslf, directs the Twins Study Center at California State University, Fullerton, and was formerly with the Minnesota Study of Twins Reared Apart (its director, Thomas Bouchard, has written the foreword). Clearly fascinated by her subject, she assumes, probably quite rightly, that interest in twins, especially identical twins, is widespread. Identical twins are, she notes, “the reflecting pools whose altered images teach us how the range of environmental influences shape developmental outcomes.” Stories about the remarkable similarities between identical twins reunited after being raised separately are irresistible, and while Segal includes them, she goes far beyond such material. She discusses in detail what twin research has revealed about individuality, identity, and questions of nature-vs.-nurture in intelligence, personality development, and athletic prowess. Segal also considers such topics as pseudo-twins (i.e., same-age unrelated individuals reared together), the special relationship of twins with each other, the effects of one twin’s death on the other, how fertility treatments have impacted multiple births, the difference between a clone and an identical twin, and twinning in the animal kingdom. Her interviews with some noteworthy twins, such as the Shapiro brothers, who both became university presidents, are especially revealing. Even the unique problems of conjoined, or Siamese, twins are treated. Its comprehensiveness and its extensive notes make this a valuable source for psychologists and other students of twinning; twins, parents of twins, and anyone who ever wished for a twin will also find much to savor here. (36 b&w photos)