Thicker than Water: Siblings and their Relations, 1780–1920 by Leonore Davidoff (review)

“Brothers and sisters,” Leonore Davidoff says at the start of Thicker than Water, “have been hovering in my consciousness for many decades,” and one can see the long gestation of this book in the great depth and breadth of reading that has gone into it (1). It encompasses a discussion of the different ways in which siblings and sibling relationships are currently understood theoretically, as well as a discussion of sibling relationships in metaphor and myth. Thicker than Water offers a helpful and insightful examination of the recent historiography of the family and of kinship among the middle classes in Britain across the nineteenth century, and considers a number of illustrative stories and case studies of particular families and groups of siblings over this same period.

Sibling relationships were not only the longest ones that many individuals experienced in this period, they were frequently the most important ones as well—both practically, in terms of how peoples’ lives were organized, and emotionally. Hence, as Davidoff argues, the tendency to ignore them and to understand families as composed primarily of parents and children—without taking into account the lateral relationships of siblings—requires some explanation. The one she offers centres on psychology broadly defined, including both the emphasis on the Oedipal triangle in psychoanalysis and the concern with the mother-child relationship in the literature on child development. She is concerned not just to assert the significance of sibling relationships in any particular family, but also to stress the ways that they extend across generations through aunts, uncles, and cousins, making up the extended kinship networks that are so important in understanding nineteenth-century British society.

The book is comprised of a series of interlinked essays, beginning by explaining the approach that Davidoff takes and the questions she asks. The volume then moves through a number of chapters dealing with relevant themes, including “close marriage” and incest; and concluding with a final section which focuses on more detailed case studies. The thematic chapters are particularly interesting, pointing as they do to some of the problems in sibling relationships that were of concern both to contemporaries and to later scholars. The chapter on “The Rise and Fall of Close Marriage,” for example, offers fascinating insights into both the extent of marriage between cousins in the early and mid-nineteenth century and to some of the concerns it generated. This kind of marriage was carefully cultivated by many different groups as a way to maintain particular communities and also to concentrate and control family capital. Sometimes, too, it was an unintended consequence of the closeness of extended families, which consistently brought cousins together and encouraged marriage. But for some, this gave rise to a concern about the possibly deleterious consequences of interbreeding and led to attempts to outlaw marriage between cousins by legislation—similar to the 1835 law which had made marriage to a deceased wife’s sister illegal. But while not legislated against, widespread social concern and the decline in the birthrate, which reduced the pool of cousins from whom anyone could choose, led to a sharp decline in close marriage.

Not all the thematic chapters work as well as this one. “Sibling Intimacy and the Question of Incest” is much less satisfactory. It offers little more than a discussion of the kinds of attraction and affection that siblings might feel for each other and a series of case studies of particularly close relationships in which the intensity of feeling raised questions about the possibility of it being sexual in nature and expression.

While the broad range of issues and relationships covered in the book provides valuable scope, it does occasionally seem like an encyclopedia rather than a monograph. This sense is exacerbated by the care that Davidoff takes to explain the connection between particular relationships and behaviours and wider social norms and expectations—so that one understands situations...