Porn viewership increases during winter, early summer

Researchers at Villanova University in Pennsylvania, led by Dr Patrick Markey, found keyword searches over the past five years relating to dirty images and movies had clear peaks and troughs, recurring at six-month cycles.

The same was found for internet searches relating to prostitution, according to a popular American magazine.

Interestingly, mainstream dating websites also experience the same spike in search traffic as pornographic sites.

But there was no such pattern for non-sexual words, which were tested as a control group, a major newspaper reported.

Though it is unclear why people appear to become more sexually active in the midwinter and early summer, one theory suggests it may be because these times coincide with the main holiday season in most western countries, when people's minds turn to leisure activities rather than work.

It can also be linked to a more biological explanation, with certain seasons being a time when we are pre-programmed to seek to reproduce.