"We all have a working idea of the self," says the intro blurb as you walk into the Wellcome Collection's new exhibition. "We know 'who we are', or think we do," it continues, in the pseudo-mystical patter of Dr Suresh from Heroes. But what follows is a barnstorming exploration of 'self' that reaffirms the Wellcome's identity as one of the best museums in London.
The exhibition is broken down into eight 'rooms', each telling the story of an individual (or two individuals, in the case of the twins room...hence the numerical disparity of the title). Samuel Pepys is perhaps the most famous. His diary is used as a hook to talk about personal journals in general. But few writers of such things are as open as Pepys. Remarkably, his complete diaries were suppressed until as late as the 1970s because of 'obscene' observations about menstruation.
Elsewhere, the exhibition tackles questions of gender identity with the remarkable tales of early sex-changer April Ashley, and androgynous photographer Claude Cahun. Naturally, there's a room about identical twins, as well as an insight into how actress Fiona Shaw gets into character.
The exploration of identity is neatly rounded off by rooms dedicated to the science behind our differences. Francis Galton's efforts to categorise humans via physical features, including fingerprints, are discussed alongside the life story of Alex Jeffreys - pioneer of DNA fingerprinting. The preposterous pseudoscience of phrenology, where the bumps on a person's head are used to intuit character traits, is also examined.
We were surprised there wasn't a ninth room (or perhaps a Room 101) dedicated to the concept of the individual in society. Government intrusion on personal liberties and the planned introduction of identity cards remain hot topics. OK, so it's hard to think of a named 'person' who would fit in with the exhibition's conceit, but perhaps the individual could simply be 'You', given that these issues affect each of us.
There are at least two hours of material here, so we'd advise a wee tea break in the cafe after room 4. As ever with the Wellcome Collection, the material has been well chosen and you'll probably want to read everything.