Former US President Barack Obama has warned against the abuse of social media and urged the importance of people meeting face to face in an interview with Prince Harry, guest-editing the BBC's flagship Today programme this morning.

In candid responses, Obama said it was 'wonderful to be able to control your day' after leaving the presidency and that it was 'liberating' to be make his own decisions about how to spend his time.

However, he said that while he did not have the same 'tools' to make a difference and had to rely more on persuasion than legislation, 'I still care about making sure the United States and the world is place where kids get a decent education, people who work hard are able to find a job that pays a living wage, conserving the amazing resources of our planet so that future generations can enjoy the beauty of this place like we did.'

He warned against the harmful effect of social media in which people were increasingly split into hostile tribes.

'One of the dangers of the internet is that people can have entirely different realities. They can be cocooned in information that reinforces their current biases,' he said.

'The question has to do with how do we harness this technology in a way that allows a multiplicity of voices, allows a diversity of views, but doesn't lead to a Balkanisation of society and allows ways of finding common ground?'

He said government could not legislate against free expression of views, but said it was important that people met face to face and not just online, instancing pubs and places of worship. People might find they have 'diametrically opposed views', but that their opponent is 'a pretty good parent or supports the same sports team'. He added it was 'harder to be obnoxious and cruel in person'.

Reflecting on his record as President and the pressures on his family life, he said that it was an 'enormous blessing that 20 million people have health insurance who didn't have before' and 'If even a fraction of them are leading better, healthier lives and are happier and some child is fulfilling their potential, then that's a pretty good score card.'

He concluded on a note of optimism, saying that in spite of the cruelty of the world, 'all the problems we see are solvable' and that if someone could choose a moment of history in which to be born, it would be today.

. Just a few generations ago, he said, 'someone who looked like me' would have been in slavery or servitude, women could only aspire to be wives and mother, and that when the Prince's grandmother - Queen Elizabeth - was already an adult, 'half the world was aflame and 60 million people were killed in a great global war'.

'If you think about how much has changed and got better, it has to make you optimistic.'