THE film Six Degrees of Separation describes a “small-world network”
where everyone in the world can be linked to everyone else through, at most, six
others. Now scientists have found that the number of “sexual links” needed to
connect two people could be even fewer.
Luis Amaral at Boston University and colleagues at Stockholm University
analysed data from a sex survey of 2810 Swedes (Nature, vol 411, p 907). By
checking how many sexual partners people had in one year, they could estimate
the number of amorous links needed to connect two people.
“Any two people might only be two or three connections apart,” says…
