Many writers take a scientific approach to their examination of human behaviour, but few do so with as much authority as 31-year-old dramatist Sam Holcroft. She combined a degree in biology at Edinburgh University with a good deal of extracurricular drama – “I was going backwards and forwards, pipetting growth hormones into dishes and then going to the theatre and putting on shows,” she says. She was eventually forced to choose between theatre and a PhD: theatre won, but Holcroft’s fascination with science has remained, especially developmental biology, psychology, and the fine line that separates civilised human behaviour from our deeper animal instincts.

Her debut play, Cockroach, performed at Edinburgh’s Traverse theatre in 2008, was an examination of natural selection set in a school biology lab. Edgar & Annabel, produced three years later for a small space at the National, was about a pair of freedom-fighters posing as a couple, their shared life playing out in a series of pre-approved scripts. And Rules for Living – Holcroft’s most ambitious work yet, to be staged in the National’s new Dorfman theatre next March – is a family drama, set at Christmas, in which relationships are dissected using the theories of cognitive behavioural therapy.

Sam Holcroft, photographed at the National Theatre. Photograph: Richard Saker/The Observer

In a small, light-filled room at the National, where Holcroft was the 2013 writer-in-residence, she describes the many similarities between writing and scientific research. “It takes huge imagination to be a scientist,” she says. “You have to conceive experiments and hypotheses, and dream up scenarios in which your hypotheses might be tested. The only difference I struggle with is the fact that in science, there is often a right answer and a wrong answer. In theatre, of course, you’re never completely right and you’re never completely wrong.”

Holcroft’s love of both theatre and science developed while growing up in London: she remembers seeing the National’s 1999 production of Look Back In Anger, starring Michael Sheen, and deciding there and then that she wanted to write plays. In Edinburgh she joined the student theatre company that has also launched the careers of playwrights Lucy Kirkwood and Ella Hickson. Kirkwood is a particular inspiration: “She has the extraordinary ability to package really complex subjects into brilliantly witty, fast-paced drama.”

Holcroft would like to write for both film and opera – her first libretto, an adaptation of a novel by the Argentinian author Julio Cortázar, was performed in Aix-en-Provence last year. But her ambitions lie ultimately in the theatre. “Theatre is changing in really exciting ways,” she says. “We now have access to video, to the most extraordinary sound design and technology. I feel like I’m only just starting to understand what it is that I love about theatre, and what it is that I want to do. And so this is where I want to stay.”





THREE MORE TO WATCH







• In the new year, Ned Bennett will direct Yen by Anna Jordan, which won the Bruntwood prize, at Manchester’s Royal Exchange.





• Set designer Georgia Lowe, who conceived the sunken pit in Alistair McDowall’s Pomona, will be working on Yen (Royal Exchange) and Amy Draper’s These Trees Are Made of Blood (Southwark Playhouse).





• Aoife Duffin made an indelible impression in the stage adaptation of Eimear McBride’s A Girl Is a Half-Formed Thing at the Dublin theatre festival. It tours to Project Arts Centre in Dublin in February.