

A towering performance in an upstanding role ... a scene from Guccione's Caligula. Photograph: Kobal

In an attempt to rid America of its phallophobia, Judd Apatow once vowed to include a penis in every one of his movies. As is particularly evident in the producer's recent offerings - Forgetting Sarah Marshall and Walk Hard: The Dewey Cox Story - Apatow has in no way reneged on his promise. But was he right about his country's fear of the penis?

There is certainly evidence to suggest the contrary, and for a period it would have seemed that male nudity was linked in some way to the seriousness with which an actor approached their role: Robert De Niro exposed himself in the name of art in Bernardo Bertolucci 1976 Novecento, while his Mean Streets co-star Harvey Keitel also stripped bare for Jane Campion's 1993 film, The Piano. The nakedness of both actors drew parallels with their daring performances, literally laying themselves bare in both their acting and their presentation. Having said that, both films were produced far away from Hollywood mainstream, and European cinema has long taken an easier line on the presentation of male genitalia.

Nevertheless, changing attitudes to the ratings system can be seen to mirror changing attitudes to the way that the penis has been included in mainstream cinema. Since 1966, when the amended Motion Picture Production Code permitted nudity in mainstream American cinema, most pictures featuring full-frontal nudity would receive the notorious X certificate or NC-17. In 1982, however, the teen sex comedy, Porky's, which featured both male and female full frontal nudity, only received an R rating instead of the usual X or NC-17. Nowadays, while you'd expect an NC-17 rating (or 18 in the UK) on films with images of full frontal male nudity, more and more are being rated R in the US (even 15 here in the UK), Apatow's recent offerings obviously among them. Even Bart Simpson exposed himself in the name of comedy in last year's The Simpson's Movie, which interestingly enough only received a PG-13 rating in the US. It would seem that nudity in animation is more acceptable than in live action features.

So why the sudden change of heart? It seems to me that comedy is responsible. In reducing the penis - rather literally - to a figure of fun, desexualising it, and thereby robbing it of its once dreadful power, the penis has only become acceptable through coming to symbolise not so much male sexuality as the fragility of masculinity. There is, after all, no denying the comedic value of what Billy Connolly once referred to as "the last chicken in Sainsbury's".

So whether it is for the sake of art or for pure comedic pleasure it would seem that the penis is penetrating its way more and more into contemporary Hollywood cinema. But in making the male member more and more into a figure of fun, are we not robbing cinema of one of its most potent symbols. Perhaps it is Judd Apatow who really fears the penis and it is he, rather than his public, who are too afraid to confront it head on, so to speak.