More Americans are Members of Facebook than Have Passports

A staggering 155 million Americans - 50 per cent of the population - are on the social network, while only 115 million people - 37 per cent - have a passport.

The number of U.S. citizens applying for passports has been rising over the last decade, but the proportion of people with the travel documents is still dwarfed by other countries.

Some 71 per cent of the population in the UK has a passport. But the U.S. is still way ahead of China, where only 1.5 per cent of the population can travel abroad.

Facebook, which was started by Mark Zuckerberg while he was a student at Harvard, has experienced phenomenal growth since it was launched in February 2004. There are now 750 million Facebook users worldwide, according to travel website Tripl, which compiled the figures.

Reasons given for the low proportion of Americans with passports include the costs of travelling abroad and the popularity of vacationing at home. Simon Winchester, who wrote 'The Best American Travel Writing', said that Americans to do have a history of international travel.