Arts review: In a Forest, Dark and Deep

Not having watched a single episode of Lost, I had few preconceptions about Matthew Fox and his much-anticipated performance as Bobby in Neil LaBute's new play, In a Forest, Dark and Deep. I understand from Lost fans that Dr Jack Shephard, Fox's character in the ABC series, is an all-round good guy, and if so this goodness remains too much on display in the character of Bobby.

It isn't just Fox's unsinister performance that leaves the play lighter and shallower than its title suggests; the material, too, seems to promise more than it delivers.

The play is set in a Hansel and Gretel-like forest cabin, which Bobby is clearing out with his sister Betty, who owns it with her husband. (At least, she tells Bobby that she owns it with her husband, but it transpires that her husband knows nothing of it.) The two immediately start sparring, and slowly Betty's past is revealed. Olivia Williams gives an engaging performance as the sister but, like Fox, she doesn't incite enough of the antipathy that her character probably deserves as she alternates between lying to her brother and wallowing in self-pity over her supposed diminishing sexual desirability. From early on, it becomes clear that Betty's story to Bobby - that they are clearing out the belongings of a previous tenant - is a fabrication. (The "tenant" is her lover.) Unfortunately, it is fairly obvious what is coming some time before each moment of disclosure.

The most interesting part of the play, though, is its examination of an area that has been particularly neglected in theatre: the mixed-sex sibling relationship. "How did we come out of the same womb?" Betty asks Bobby.

Audiences are familiar with single-sex siblings on stage and are used to the relationship between siblings being represented as adversarial. The Cain-and-Abel trope has been a common way of exploring rivalry and competition both within the family and in the wider political context. Think of Eteocles and Polynices in Aeschylus' Seven Against Thebes, who kill each other in single combat; Goneril and Regan's competing acts of obsequiousness at the expense of their sister Cordelia in King Lear; or Alonso's usurpation of Prospero in The Tempest.

Occasionally theatre has stretched this focus to consider what happens when siblings have differences of character and ideological outlook. Go-getting Thatcherite Marlene and domesticated socialist Joyce in Caryl Churchill's Top Girls are a case in point. More extreme examples of sibling estrangement can be seen in plays such as Willy Russell's Blood Brothers or Mark Ravenhill's Over There, works that explore the differences between siblings who are reunited in adulthood after growing up in isolation from each other.

An opposite convention, sibling loyalty, is expressed between the Goths and the Roman Andronici in Shakespeare's Titus Andronicus, and explored in the relationship between the reunited twins in The Comedy of Errors. LaBute's rather more "dark and deep" 2007 play about brothers and childhood abuse, In a Dark Dark House, now to be considered the companion piece to In a Forest, Dark and Deep, takes up this theme as well.

But either way, a focus on mixed-sex siblings remains unusual. Looking back to the Greek classics, the relationship between Electra and Orestes as imagined in Aeschylus' Oresteia represents brother-sister loyalty as the norm, but there has been little follow-up. In Shakespeare's Twelfth Night, the stage encounters between Sebastian and Viola are noticeable for their infrequency. The exceptions are the later Jacobean plays, such as John Ford's 'Tis Pity She's a Whore and John Webster's The Duchess of Malfi, where sex, violence and incest become central tenets of the mixed-sex sibling connection.

Indeed, incest seems to dominate the way in which this relationship is expressed in modern theatre - for example, in Stephen Poliakoff's 1975 play Hitting Town, Sam Shepard's Fool For Love (1983) and one of the eight stories of Simon Stephens' Pornography (2008). Yes, there are examples of mixed-sex sibling relationships where incest is not apparent, such as debbie tucker green's Random (2008), but here the brother-sister relationships tend not to be the main focus of theatrical enquiry.

So why has the brother-sister relationship been neglected on stage? One answer could be a residual sexism that still influences the kinds of roles written for women. If the female role goes beyond sisterly loyalty to the male protagonist, it is likely she will figure not as a driver of narrative, but as the object of romantic or sexual desire. It then becomes difficult to represent a brother-sister relationship on stage without sexualising the connection, which returns us to the incest taboo.

In In a Forest, LaBute manages both to allow his female protagonist to drive the narrative - and to consider incest. Betty is the reason that the cabin is being cleared. Her alternating acts of deception and disclosure structure the play. But at the same time this casts her as the femme fatale, worthy of being the object of Bobby's sexual sparring. He jealously accuses his sister of sleeping around with his friends, calling her a "bitch", "slut" and "whore". His memorable line "fuck you sis, I mean that from the heart" pre-empts a moment of attempted rape. Betty's full recovery from her initial shock and disgust at Bobby, though, seems to suggest a more complex relationship between the two.

The siblings' rivalry here is played out rather comically at times as class difference, and fun is had at the expense of academics. Betty is a college lecturer and newly appointed faculty dean, while Bobby is a labourer. Betty's impending sabbatical is translated by Bobby as "dicking around with novels". Bobby's interpretation of their wage differential is "same salary, less months". After Betty has confessed that she had a student lover staying in the cabin, she explains that part of the attraction was "Oh my god, he's actually read the material". We are told that they got together at a "semiotics conference". More soberly, Bobby's questioning of the utilitarian value of English literature resonates with the research excellence framework impact agenda and the threat to humanities from the marketisation of higher education.

A second answer to why mixed-sex sibling relationships are infrequently the focus of the theatrical gaze is perhaps that we don't have much in the way of psychoanalytical models for horizontal familial relationships. We lack an agreed set of ways, a discourse if you like, for thinking about brother-sister relationships from which to draw on stage. The vertical model - the deterministic effect parental figures have on the psychosexual development of children - dominates our thinking, at the expense of considering lateral relationships.

Feminist psychoanalyst Juliet Mitchell takes this up in her 2003 book, Siblings. She begins by asking if Oedipus had a sister. The answer is yes, of course; he had two, Ismene and Antigone. But in order to negate the incest taboo, the sibling connection has been effaced in our memories in preference to the parental relationship. Mitchell uses the Oedipus complex as a metaphor for the absence of a sibling paradigm in psychoanalytical models.

While Oedipus' murder of his father and sex with his mother were separate acts, siblings unconsciously simultaneously desire to murder and have sex with the same person, Mitchell says. They need to overcome this sibling trauma if incest and an "unestablished self" are to be averted. In a Forest could thus be read as Bobby's failure to negotiate the sibling trauma phase of his development, which results in his aggressively sexualised interaction with his sister. But ultimately it's a shame that LaBute didn't bring anything fresh to the mixed-sex sibling relationship. Again it is imagined, too conventionally, as rivalrous and incestuous. The brother-sister affiliation is an autonomous relationship, which deserves to be considered through new models.