And it is these sexually hyper-active individuals that should be targeted in safe sex campaigns, say researchers at Stockholm University, as the consequences are likely to be more widespread should they contract a sexually transmitted disease.
On account of the relatively few people who get to know an unusually large number of sex partners, many people are more intimately linked than they may care to imagine.
And it is these sexually hyper-active individuals that should be targeted in safe sex campaigns, say researchers at Stockholm University, as the consequences are likely to be more widespread should they contract a sexually transmitted disease.
Diseases such as chlamydia, gonorrhoea and HIV infections are on the increase worldwide.
Last year, there were 36 million people living with HIV or Aids across the world - 50% more than the World Health Organization predicted in 1991.
Earlier this month, the UK announced that the number of HIV infections is growing at the fastest rate yet. And American researchers released a study suggesting that one in five teenagers has an undiagnosed sexually-transmitted disease.
Footloose and fancy-free
Frederik Liljeros and his colleagues at the university questioned 2,810 Swedes aged between 18 and 74 about their sexual behaviour.
After applying a mathematical model to the results, they found that those with the most sexual partners act as the node - or centre - of a web of human contact.
These networks are highly susceptible to the behaviour of the best-connected "nodes", such as whether they use a condom when having sex.
The research is published in the journal Nature.
Six degrees of copulation
The research echoes the concept of six degrees of separation, the theory first posed in John Guare's play of the same name that everyone in the world is just six acquaintances away from anyone else.
It has since been used in the film trivia game Six Degrees of Kevin Bacon, in which players try to link any actor, living or dead, to the Footloose actor within six films.
Thus Oscar-winner Dame Judi Dench can be linked to Bacon in just two easy steps, even though the pair have never coupled on celluloid.
She played M in The World Is Not Enough with Denise Richards, who appeared in Wild Things with Bacon.
Now, just apply the same principle to your personal life...