Some of the most important relationships in life begin before we have any knowledge of them. That unsettling truth lies at the heart of the remarkable story of two Indian-born women, adopted separately in infancy, who became close friends as teenagers in the Netherlands and only decades later discovered that they were biological sisters. The extraordinary element is not the DNA test itself. Genetic testing has made such discoveries increasingly possible. What is extraordinary is that the relationship existed before the explanation. As teenagers, the two women recognised similarities in appearance and behaviour and developed an immediate intimacy.

They eventually lost touch, lived separate adult lives and built their own families. Yet the connection had been real even when its biological basis was invisible. That should complicate the way we think about family. Modern societies tend to define family through a mixture of biology, law and shared upbringing. Adoption, however, exposes the limitations of each definition. A child may have biological parents who are strangers, adoptive parents who are unquestionably family, and siblings whose existence remains unknown. None of these relationships cancels the others.

Identity can contain several truths simultaneously. For adopted........

© The Statesman