Having overslept the press preview last week, I took a little longer than usual to get along to Wellcome Collection’s latest major exhibition. Eight Rooms, Nine Lives explores issues of identity – what determines who we are, and how are we each distinct from one another?

I went in not really knowing what to expect. As is often the case with the Wellcome Collection, the theme feels somewhat intangible – almost, ironically, lacking identity. But, as usual, they’ve pulled it off with aplomb.

The exhibition sprawls throughout the ground floor area in a series of partitioned 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). I’ll briefly walk you through each:

1. Claude Cahun. The tale of a photographer born in 1894 who chose an androgynous identity for herself, got imprisoned by the Nazis on Jersey and shaved her hair off at a time when this would have been considered outrageous for a woman. An unusual biography, and perhaps a curious one with which to start the exhibition.

2. Samuel Pepys. An exploration of diaries and why people keep them. I was amazed to discover that the complete Pepys was not published until the 1970s because of references to menstruation!

3. April Ashley. One of the first people to undergo a sex change operation, taking the unusual career path of joining the merchant navy as a man, modelling for vogue (as a woman) and marrying a Lord.

4. Fiona Shaw. Video installations show how this actress of diverse roles ‘becomes’ her character. I found this one a bit tiresome, to be honest. But that’s just me, and I defend my right to express my individuality in an exhibition about identity.

5. Franz Jospeph Gall. No, I’d never heard of him either. Turns out he was the fellow who popularised phrenology – the reading of character based on the bumps of the head. Now I have a very visible bump on the back of my bonce. According to the charts, its location suggests I am deeply venerating of God. Hmmm. Think I’ll get it removed.

6. Francis Galton. I’ve only had fleeting acquaintance with the work of this cousin of Darwin, and namesake of UCL’s Galton Laboratory. The small display on his life here makes me want to find out more about this prolific and resourceful individual. The exhibition charts his life works, with particular emphasis on his efforts to classify humans into type, based on physical properties – including fingerprinting.

7. Alec Jeffreys. This room, adjoined to Galton’s, was my favourite, and will no doubt appeal to most Nature Networkers. Jeffreys developed DNA fingerprinting. The exhibition includes fascinating letters from the government seeking to use his techniques to aid criminal investigations into identity. Jeffreys’ own identity is also captured by a number of personal effects from his childhood and early career.

8. Charlotte and Emily Hinch. The Hinch family have produced three generations of identical twins. The latest duo were born some years apart, thanks to IVF. The room explores what it means to grow up alongside someone who looks just like you.

Various mirrors can be found in the interstitial space between rooms, as a reflective diversion on identity. Ancient polished metal from Egypt and the Etruscan civilisation are displayed alongside a clever ‘time-lapse’ mirror and one that reflects a ‘correct’ image of your face rather than a reversed one.

So, once again, Wellcome Collection delivers a thought-provoking and essential exhibition that reaffirms its own identity as one of the best museums in London.

Identity: Eight Rooms, Nine Lives runs at Wellcome Collection until 6 April 2010. Look out for the related events, coming next year.