I like to go to the theatre to learn things. But while this devised piece by the David Glass Ensemble deals with a fascinating subject - the affinity between human and primate - it allows form to dominate content. Like a lot of physical theatre, it is more an exhibition of virtuosity than exploration of an idea.
Glass's starting-point is the work of American child psychologist Roger Fouts in teaching sign language to Washoe, a chimp. Over 30 years, we see Fouts's growing relationship with his subject, his tussles with academic institutions in Nevada and Oklahoma and his realisation that he is fighting a losing battle with an environmentally hostile world in which primates are caged or slaughtered. We are warned that, if we go an as we are, chimpanzees will be virtually extinct in 10 years' time.
The five-strong ensemble certainly demonstrates the similarities and differences between man and ape. In an opening scene, students cluster round library shelves in simian style and Fouts's future wife conducts her own mating ritual by leaning across a desk with her bottom suggestively arched. But the show loses sight of its central theme: the process by which Fouts taught Washoe sign language. In place of scientific procedure we get a confusing display of theatricality.
Too much is unexplained. At one point Fouts trades his academic rights in Washoe's story for the chimp's freedom, but the price paid for this is never explored. The idea that Washoe may have displaced Fouts's own family is also arbitrarily introduced. Instead of following up such scientific intimacy, Glass's show dazzles us with trickery: actors scale telegraph-poles and crouch in junction-boxes, and flashing lights evoke the nightmare of animal captivity.
To his credit, Glass avoids sentimentality: he is rightly scathing about an Oklahoma therapy group that baptises animals and talks about "finding our inner chimp". And he heightens our awareness of their exploitation. But although his cast, led by DV8's Liam Steel as Fouts, display remarkable versatility, I can't help feeling that the show subordinates ideas to physical expressiveness. Washoe may have learned, in a sense, to speak. But what did the experiment do to Fouts?
· Until Sunday. Box office: 020-7223 2223 .
