Decreation, Sadler's Wells, London

William Forsythe's Decreation is about jealousy. It concerns people fragmented and alienated by strong feeling, disconnected from each other. In practice, Forsythe is so busy ironising and deconstructing their emotions that it's hard to care.

Decreation is the centrepiece in Sadler's Wells' Focus on Forsythe season, one of the biggest stage works in a programme that covers the American choreographer's art/performance installations. The gap between his staged performances and installations is narrowing. Decreation uses film and often distorted speech, as well as dance.

The piece is based on an essay by Anne Carson, which examines jealousy, love and God. Standing behind a podium, Dana Caspersen launches into an argument – playing out both sides – pulling at her shirt to suggest different voices or a divided self.

She complains about affairs, confronts a lover, dismisses complaints. The argument goes round and round. At last, Caspersen falls behind the podium – to be replaced by a different dancer, who goes through the same argument. It's going to be very familiar by the end of this show.

The quarrel is melodramatic; speeches are delivered self-consciously. Given the scaffoldings of irony and deconstruction that Forsythe builds up around these relationships, he may be undercutting them from the beginning. But it sounds like bad acting.

A camera crew films the speakers, projecting their images onto the podium. Voices are drowned out by electronic clashes. In one part of the text, a lover accuses another of being operatic. Sometimes they launch into song.

Dancers wander across the stage, stumbling, feet turned in or twisted onto their sides, faces contorted. One man staggers forward, arms outstretched as if for crucifixion. They pull at their clothes, lifting up layers to show bare skin. At last, a dancer – followed by the others – rolls on an inky tabletop, her body covered in dark smears.

This isn't new. Pina Bausch was choreographing shouting, flailing and tugged costumes 30 years ago. Forsythe work is less visceral. His dancers behave as though they're in extreme states, but they don't make them vivid. Carson's essay is about moving beyond the self; Forsythe's angst is too self-conscious to get there.

Focus on Forsythe season runs to 10 May (0844 412 4300; www.sadlerswells.com)