When was the last time you changed your mind? If you're struggling to remember, then it turns out you're not alone. Confirmation bias, the subject of Chris Thorpe's fascinating new collaboration with director Rachel Chavkin, ensures that we are rarely convinced of the opposite point of view, instead seeing the world around us in a way that confirms existing beliefs. As humans, we are hardwired to reinforce our own opinions at every turn.

What happens, then, when we come face to face with another set of beliefs? In an attempt to push at the edges of confirmation bias and explore how it works in action, Thorpe has been engaging in an "honourable dialogue" with a white supremacist – an individual whose views are violently, irreconcilably opposed to his own. The resulting show shares this dialogue, prying it and Thorpe's role within it apart to examine just how we look at the world.

The answer is with our own stubbornly blinkered eyes. Just as any experiment sets out with a hypothesis, we interpret the information we encounter with our conclusions already in sight. Thorpe, who performs the piece alone (with a little help from the audience), tests this out with psychological number games, with thought experiments, and through recalled discussions with Glen, the staunch neo-Nazi he has established a dialogue with.

But all that we are really confronted with on stage is a facsimile of difference, the echo of an opinion that sharply contrasts with the beliefs held – one assumes, at least – by Thorpe's audience. Glen (a pseudonym in any case) is never seen or heard, his voice instead channelled through Thorpe or through audience members who are asked to read aloud his words. Disembodied in this way, he becomes a little like the imaginary antagonists that we set up only to knock down in the self-affirming story of our lives. Our biases are once again confirmed.

Yet neither is it quite this simple. Thorpe and Chavkin's show is a sly, slippery thing, tickling at the mind for long after. It's delivered, meanwhile, with an aggression and conviction – on both sides of its dialogue – that complicates its reception. The real brilliance, however, lies in the show's delicate plaiting of concept and form, theatrically grappling with its ideas at every level.

Or maybe I'm just seeing what I want to see.

Confirmation runs at Northern Stage at King's Hall until 23 August

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