The world of internet pornography is a pervasive and wide reaching technology, growing at a breathtaking rate. It is a $13 billion-a-year industry in the US. Nine out of 10 boys in America are exposed to it before the age of 18, and men are 543% more likely to be users than women. By 2017, over a quarter of a billion people will use mobile porn sites worldwide.

With such an enormous audience, it is not possible to make generalisations about whether internet pornography is good or bad. Clearly, it’s a matter of perspective. Reviews have linked pornography consumption with positive effects such as increased sexual knowledge and more liberal sexual attitudes. But how does it shape our intimate relationships?

British Prime Minister David Cameron has expressed concern that internet pornography could be warping ideas about sex and relationships, and scientific evidence in this area tends to support his view. Links between pornography consumption and intimate relationship problems (although data typically refer to heterosexual, monogamous relationships) are well established.

Pornography consumption has been associated with increased marital distress, risk of separation, decreased romantic intimacy and sexual satisfaction, a higher chance of infidelity, and compulsive or addictive sexual behaviour. However, this does not automatically imply that internet pornography causes relational difficulties. Pornography consumption may equally be caused by them.