Following reports Facebook manipulated the feeds of almost 700,000 users, the site has issued a statement claiming it ‘never met to upset anyone’.

During one week in 2012, the social media giant edited feeds to highlight either positive or negative items, and then monitored responses.

The site has since apologised for the way the paper described the research, and any anxiety that was caused, adding, ‘the research benefits of the paper may not have justified all of this.’

‘The reason we did this research is because we care about the emotional impact of Facebook and the people that use our product,’said Facebook data scientist Adam D. I. Kramer.

‘We felt that it was important to investigate the common worry that seeing friends post positive content leads to people feeling negative or left out.

‘At the same time, we were concerned that exposure to friends’ negativity might lead people to avoid visiting Facebook. We didn’t clearly state our motivations in the paper.

‘Having written and designed this experiment myself, I can tell you that our goal was never to upset anyone.’

During the experiment, Facebook deprioritised content in News Feeds, based on whether there was an emotional word in the post.

Tests affected around 0.04 per cent of users — or 1 in 2500 — for a week, in early 2012.

According to Kramer, nobody’s posts were ‘hidden,’ they just didn’t show up on some feeds.

‘Those posts were always visible on friends’ timelines, and could have shown up on subsequent News Feed loads.’

It found that negative posts elicited a swell of positive responses, but also that a reduction in positive news led to more negative posts, according to the results of a study published in PNAS Journal.