Well, now, there is stuff about pornography - all those issues of slavery, abuse and misogyny, just for starters – that's a pretty firm turn-off, but the fact is that the question of what turns men and women on is, as always, rather more complicated. It's rather, well, easier to tell whether a man is turned on or not; women find it easier to hide; even, it seems, from themselves.

Psychologists at Amsterdam University, investigating whether women are slower to arousal than men, cobbled together a rather odd contraption, essentially a chair with electrodes, which was able to accurately measure the levels to which the pudenda were reacting to stimuli. They also attached a lever which the subject could manipulate by hand to register her own perceptions of her levels of arousal. Then, they showed a test group of women a series of porn films. One was of the classical "male" porn fantasy set which so many women seem to dislike: the whore-centered, foreplay-free objectified instant-shag type of film. Then they showed them a film designed to appeal to women: one with some storyline, and more of what might be called "erotica," rather than straight shagging.

According to the measurements of genital arousal, all the women were, in fact, turned on by both types of film; they showed engorgement in equal measure. Women more used to watching porn tended to be more easily aroused, and older women were generally less aroused than younger ones, but the fact remains that they all reacted. Psychologically, though, the results told a very different story. Assessing their own perceptions (by manipulating the lever), the women barely registered the male-centered film as arousing and described it in very pejorative terms.

So, does this mean that women are liars? Well, not really. What it probably means is that, while a man with a stiffy is a man with a stiffy, there are two equally important elements to female arousal: the physiological and the psychological. The majority of women just don't like sexual material that's humiliating or fails to acknowledge the full humanity of the individuals involved. Their bits may disagree, but their minds are more powerful. So, yes, if you don't get turned on by porn then you don't get turned on by it. I'm afraid your poor old boyfriend's on a hiding to nothing if he thinks he'll be able to change your mind.

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