It was the French psychologist Alfred Binet (1857-1911) who coined the term "sexual fetishism". He meant it to describe individuals with sexual interests in non-human objects such as clothing.
The word "fetish" comes from the Portuguese feitico, meaning "charm" or "sorcery".
In the past three years, sales of erotica literature have increased by 25 per cent (according to Nielsen BookScan).
A pair of high heels may be the world's favourite fetish, according to the largest ever study of sexual kinks. Asked to name their favourite body parts, sexually speaking, 47 per cent of those asked named feet and toes; where objects related to the body were concerned, footwear polled 64 per cent. Other objects that people were turned on by included hearing aids and pacemakers.
Giovanni Boccaccio's Decameron (1353) must be one of the most censored erotic books of all time. The Italian work features tales of lechery by monks and the seduction of nuns from convents and was banned in many countries after its publication. Five centuries later copies were still being seized and destroyed by the authorities in the USA and the UK and between 1954 and1958 eight orders for destruction of the book were made by English magistrates.
About 90 per cent of people often think about someone else during sex with their partners, according to a survey of British sexual fantasies. As well as imagining famous faces, around a third of respondents said they fantasised about sex with a work colleague or a friend, and a quarter with a friend's partner.
A study from the University of Montreal in 2007 found that women were more likely than men to visualise current or past partners (as well as celebrties) in their erotic imaginings. Men, by contrast, veered towards imaginary people.
Not everyone is turned on by feet. The Australian neurologist and existential therapist, Viktor Frankl, once noted a case of a man whose sexual fetish involved frogs and glue (at the same time).
Fifty-eight per cent of respondents in a global survey by the condom manufacturer Durex said that they deemed it acceptable for products aimed at improving sex lives to be available in mainstream stores.
The same percentage 58 per cent said, in a different survey (by psychotherapist Brett Kahr), that they regularly fantasise about sex with a regular partner. Other findings: 35 per cent of men fantasise about sex with two women; 19 per cent like to be watched; and 3 per cent fantasise about sex with animals.
The other widely shared fetish is BDSM which stands for Bondage, Discipline and Sadomasochism. Technically, it is illegal for a person to engage in S&M activities that leave a lasting mark on someone else's body.
The Marquis de Sade (left), whose licentious writings in the 18th and 19th centuries gave birth to the term "sadism", was only 5ft 2in tall. Known as the "philosopher of vice", he spent more than 30 years in prisons and lunatic asylums.
Sixty per cent of the visitors to last year's Erotica show in London were women
The Paris Museum of Eroticism contains more than 2,000 erotic objects, from sacred Indonesian phalluses to watercolours of the Kama Sutra.