He found that there was very little correlation between having friends on social networks and actually being able to depend on them, or even talking to them regularly.

The average person studied had around 150 Facebook friends. But only about 14 of them would express sympathy in the event of anything going wrong.

The average person said that only about 27 per cent of their Facebook friends were genuine.

Those numbers are mostly similar to how friendships work in real life, the research said. But the huge number of supposed friends on a friend list means that people can be tricked into thinking that they might have more close friends.