A new report from the Reuters Institute for the Study of Journalism provides further evidence of how social media is shaping news consumption.

The survey of online news consumers across five countries – UK, US, Germany, France and Denmark – found that social media is starting to challenge search engines as a primary way of finding news.

In the UK, 30% find the news through search, compared to 20% who come across the news on Facebook or Twitter.

But the study found a significant generational difference in news discovery. Young people (43%) are far more likely to find the news through their social circles.

However, not all sharing is equal. Digging into the data, the study discovered that there was a core of heavy news consumers who have a disproportionate influence on the sharing of news.

The group made up 7% of the sample, but they share news more than twice as often as the overall online news consumer.

Twitter was the network of choice for this small group, which the report says “backs up a growing body of evidence around the special importance of Twitter for news.”

The study also provides further evidence that people are more likely to click on a link from a friend, colleague or acquaintance, compared with a link from elsewhere. A 2010 Canadian study I was involved in also found that news consumers also were twice as likely to get news links from friends than from news organisations.

It will come as no surprise to hear that Facebook is the most important social network for news, making up half of all news sharing in the UK (55%). Email was next at 33%, followed by Twitter at 23%.

The key role of Facebook in sharing the news is partly due to the development of social newsreading apps by prominent news outlets such as the Guardian and the Washington Post. The Facebook apps make it easy for someone to share a story with their social circles.

The importance of sharing varied across news brands. For example, 21% said they came across a BBC news story through social discovery, compared to 41% for the Guardian and 46% for the Independent. As the report notes, “both newspapers have  been active in social media and launched ‘social reader’ applications in Facebook – which automatically share stories that you have read – without having to take any other action”.

It may also be that the newspapers will have the type of content that lends itself to sharing. They are more likely to have commentary and opinion pieces that provoke a reaction from the audience than the BBC News website which abides by the corporation’s impartiality guidelines.

The full report is available as a PDF, as well as the raw data.