Autism and Asperger’s Syndrome are concepts which seem to have been talked about for the best part of fifty years, and yet are rarely touched upon by Hollywood.

Apart from Rainman of course. And that film chronicling the life of a certain Mr Gump.

The indie sector has fared better in this regard, offering several contemplative and pared-down portrayals of the subject concerned.

I say all this as Morgan Matthews’ charming new film X + Y may be marketed as some sort of teen rom-com, but make no mistake: the film is primarily about those who live on the autistic spectrum, the dreams they follow and the obstacles they face.

The film is based on Matthews’ BBC documentary Beautiful Young Minds, which focussed on Daniel Lightwing, a York teenager with Asperger Syndrome.

Nathan (Asa Butterfield), the character through which Lightwing’s story is recounted, is a teen math prodigy.

Nathan has been tutored and trained for several years by the cantankerous Mr Humphreys (Rafe Spall) and has long dreamed of representing Britain in the International Mathematical Olympiad.

Think Little Man Tate and you’re on the right track.

X + Y follows Nathan’s journey through the selection process and the training camp in Taiwan, right up to the competition itself at Cambridge.

Simply put, this is a beautiful and warm film, brimming with heart. Admittedly it veers close to familiar love-versus-logic territory at times, but manages to avoid ever descending into gloopy sentimentality.

The documentary style also saves the film from patronising towards those who either suffer from or are largely uninformed about autism as a condition, retaining instead a respectable degree of objectivity.

This doesn’t mean that tears won’t be jerked: just wait for the scene involving a Monty Python recital. Heartbreaking stuff.

As Nathan’s mum, the always reliable Sally Hawkins brings credible angst to her character, channeling just the right blend of love and frustration, whilst Spall proves a suitably wry, and at times tragic, mentor figure battling with his own challenges.

Rounding out a trio of excellent supporting performances is Eddie Marsan, as the UK team leader, with a turn that nicely complements Matthews’ storytelling style.

Special praise goes to Butterfield in the main role. Last seen in box office flop Enders Game, he gets to prove his acting chops here with a nuanced portrayal of Nathan, right down to every facial tic and body movement.

The only negative point was the inclusion of love story subplots for both young and older characters alike. Admittedly, Lightwing did meet his Chinese wife-to-be during a gap year abroad, but the film

imposes a love triangle set-up on proceedings. Such strands feel a little shoehorned, and are presumably intended to inject drama into the documentary-like proceedings. Instead they serve to dilute it.

Don’t let this minor quibble put you off: this is a surprisingly feel-good film which will leave you feeling that little more empathetic, and possibly celebratory, towards the differences between people.

Jonathan Campbell