The title of John Guare’s play, first staged in 1990, has become a touchstone of popular culture — a succinct if scientifically questionable way of expressing our sense that it’s a small world.

In truth, the best thing about the piece is its suggestive name.

Based on the story of real-life con artist David Hampton, and influenced by the theories of psychologist Stanley Milgram, it contains some zingy moments, but it’s a gimmicky and rather dated satire, packed with knowing allusions and pleased with its lightweight philosophising.

Paul, an articulate young black man, turns up unexpectedly at the home of art dealer Flan Kittredge and his wife Ouisa on New York’s Upper East Side.

They live beyond their means, are noxiously materialistic, and affect a chic liberalism — which Ouisa eventually disavows. At first the Kittredges treat Paul with anxious scepticism.

But soon he ingratiates himself, persuading them that he is their children’s Harvard classmate and then holding forth about old movies, Freudian theory and the subversive effects of The Catcher In The Rye.

Paul goes on to allege that he is the son of film star Sidney Poitier. (In fact Poitier has six daughters and no son.)

He even claims he can get the Kittredges minor parts in his father’s improbable-sounding movie version of Cats.

Overwhelmed by his charisma — which is really chutzpah — they are comprehensively suckered. In this, it emerges, they are not alone.

David Grindley’s production is elegant, enacted on a set by Jonathan Fensom that seems inspired by the works of Mark Rothko.

The comic notes are hit with confidence, and the key performances are well-defined.

Obi Abili is charming and compelling as Paul, and Lesley Manville convincing as the smart, neurotic, mutable Ouisa, whilst Anthony Head’s Flan is unsurprisingly suave. Yet pathos is lacking, and so is credibility.

Although the action takes place at a time when apartheid is said to be in force, the children of the Kittredges and their prosperous friends are dressed in today’s fashions, and their manner suggests they’ve parachuted in from a completely different play.

Moreover, Guare’s device of having characters address the audience directly is grating, and we are left wishing they were less like hard-edged objects and more rounded emotionally.

Grindley’s production intriguingly hints that our lives are all confidence tricks. It has pace and wit, but not in the end a great deal of substance.

Until 3 April. Information 0870 060 6628.