File photo: Instead they spend longer chatting online with cyber friends they may never see face-to-face.

London - We now spend so long on social network sites that the amount of time spent mixing with friends and family has slumped dramatically.

The rise in the internet means only six in ten adults now socialise at least once a week, down from seven in ten a decade ago, official figures show.

Instead they spend longer chatting online with cyber friends they may never see face-to-face. Yet experts claim this may not be entirely bad.

Over just five years, the share of adults who conducted much of their social life over the internet rose by more than a quarter, according to analysis by the Office for National Statistics. Separate research shows that in 2015 two-thirds of us were using social media, exchanging emails and making internet phone calls, as well as playing games, watching films or listening to music online, sometimes instead of going out.

The ONS report on social capital – the links that make a well-functioning and close-knit society – said economic growth and individual well-being depend on us having good social lives.

However we are increasingly less likely to spend time in convivial surroundings with friends or colleagues, and family gatherings are becoming more infrequent.

The decline in the habit of going out has coincided with large-scale pub closures and an unprecedented collapse in alcohol consumption.

The number who go out with friends, relatives or work colleagues at least once a week was recorded in 2014 as 61 percent, down from 69.8 percent in 2006 – showing that nearly four in ten of us rarely socialise. The report, based on large-scale official surveys, interpreted the fall in numbers meeting in groups as a good thing.

"Research into the relationship between social networking and social capital is still in its early stages but early research suggests that social networking may help bolster social capital in the form of helping people strengthen relationships and aiding integration within communities," the ONS report said.

"We have therefore interpreted the increase in social networking as an improvement."

The declining habit of going out with friends and colleagues is the latest evidence pointing to a transformation in millions of lives since the arrival of the internet, one which has accelerated quickly since the mass take-up of social media, including Facebook and Twitter, since 2007.

Over the past few years there have been deep falls in numbers of young people drinking alcohol, smoking or taking drugs, and a collapse in numbers of teenage pregnancies.

In contrast, the numbers spending time online have been rising fast.

In 2011, 45 percent used the internet for emails, phoning, social media, games, entertainment or window shopping. By 2015, it was 63 percent.