File picture shows couples kissing on Valentine's Day in Paris
Where are people most unfaithful? Who uses sex toys? On a darker level, where is child rape more prevalent? French geographers have tried to answer these questions and others in a global atlas on sexuality.
From legislation and the dynamics of couples to prostitution and violence, the book maps out the evolution of sexual habits and acts around the world by collating various surveys, figures and reports already available.
"Sexuality is everywhere on our city walls and on our screens, in lighter news or in darker events," said Nadine Cattan, research director in geography at France's National Center for Scientific Research.
"We wanted to cover all this worldwide to try and understand it a bit better," she said, adding the research had lasted 18 months.
The atlas covers multiple areas, such as what it calls a "sexual and amorous transition" happening in Europe, where infidelity is on the rise.
Using data drawn across five European countries from the 1.5 million members of Gleeden -- a dating site for married people who want affairs -- the atlas pinpoints Paris as the city where most people are unfaithful.
According to the data, more than half of those who cheat on their partners are highly educated, and 22 percent work in finance, banking or insurance. The major reason cited for infidelity is a desire to test their seduction power.
In its chapter on couples, the atlas also explores other sexual habits, such as the frequency of sexual intercourse or the level of satisfaction.
In Greece, Poland and Brazil, some 80 percent of the population think sex is very important, while in Thailand and Japan just 38 percent do, it says.
In Europe, people in Britain, Norway and Sweden are the most avid users of sex toys, citing a report by condom maker Durex, while southern countries including France are not that interested.
On the much darker side of the matter, the atlas collates figures on prostitution, sexual violence and discrimination.
Sweden held a European record for the number of registered rape complaints in 2008 -- or 53.2 out of 100,000 inhabitants -- although the atlas points out the country's legal definition of rape is much broader than in other nations.
It adds that many countries have taken measures to address sexual harassment, such as women-only bus lines in Mexico and similar initiatives in cities in Brazil, Egypt and Japan.
But in Europe, only 14 percent of rape complaints lead to a conviction, the United Nations Office on Drugs and Crime says.
And on that same continent, Northern Ireland held the unenviable record in 2008 of complaints of sexual assaults on minors, according to the same organisation.
Prostitution and pornography are also widely covered. According to the data, 98 percent of porn is made in the United States and the remaining two percent in other nations, mainly Russia, Hungary and the Czech Republic.
The sex trade, meanwhile, has exacted a heavy toll on biodiversity due to those who take aphrodisiacs to improve their performance -- Vietnam, China and South Korea being in the lead.
Rhinoceroses have been particularly hard hit due to the belief that their horns are hugely powerful aphrodisiacs, with the animal decimated in Africa.
Such is the demand that thieves have stolen rhino horns in dozens of museums, zoos or other institutions across Europe and South Africa, as detailed in maps.