Scarlett Johansson has been cast in 'The Psychopath Test'.

The 30-year-old actress has agreed a deal to star in the film adaptation of Jon Ronson's book of same name.

Brian Grazer and Roach will produce the project, according to Deadline, which also claims Erica Huggins and Jennifer Perini will act as executive producers.

The original synopsis of the book explains: ''What if society wasn't fundamentally rational, but was motivated by insanity? This thought sets Jon Ronson on an utterly compelling adventure into the world of madness.

''Along the way, Jon meets psychopaths, those whose lives have been touched by madness and those whose job it is to diagnose it, including the influential psychologist who developed the Psychopath Test, from whom Jon learns the art of psychopath-spotting.

''A skill which seemingly reveals that madness could indeed be at the heart of everything...''

Johansson's casting in 'The Psychopath Test' comes shortly after it was confirmed she will reprise the role of Black Widow in 'Captain America: Civil War'.

Director Anthony Russo shared: ''We've been preparing for the movie since the one debuted last year. So, we've been working on it for a long time now.

''We're very happy how it's coming along... It's going to star Chris Evans as Captain America, Scarlett Johansson will be back, Winter Soldier [Sebastian Stan] will be back, and Robert Downey Jr as Iron Man will also be joining us in the next film.''