When William Viney writes about twins, he knows whereof he speaks. Th e author is himself a twin and his meticulously researched narrative of superstitions, fantasies and experiments reveals the ways in which twins have long fascinated us and played a part in shaping our world.
Viney sets out to bust the myth, commonly reported in the media, that twinship is an unusual or rare phenomenon. Th e fact is that one in 30 people in Europe or the USA is likely to have a twin brother or sister. Th e incidence is less frequent in East Asia, where only one in every 70 people on average is a member of a twin pair. But then we fi nd the highest population of twins anywhere in the world in Nigeria, where one in 12 is a twin. Th e causes of these disparities are drawn from a complex confl uence of biological and social variables that link genetics, reproductive behaviour and access to advanced medical technologies such as IVF. Viney sets out this science, explaining that twins come in two types: dizygotic, who may be of the opposite sex; or monozygotism – identical twins who are always of the same sex, the result of a single fertilised egg splitting and producing two babies.
So much for the science. From here, the book sets out to explore how twins have been variously feared, studied and schooled in society. Viney looks closely at the many observers of the twin phenomenon and examines their legacies. Twins haven’t always had an easy existence. Th ey have been honoured as gods but also destroyed as toxic dangers; viewed as essential to scientifi c practice yet held up as emblems of science dangerously out of control.
Viney explores what twins have meant to civilisation, from Homer’s vision of Castor and Pollux to the extraordinary story of two 21st-century twins in the USA who were separated at birth. Reunited years later, they found they shared striking similarities, including heart problems and insomnia. Leave it to that country to come up with the celebration of ‘Twins Day’, an annual festival held in Twinsburg, Ohio, that attracts thousands of twins and is today the largest festival of its kind in the world.