By Harriet Alexander
Facebook has conducted a secret massive psychology experiment on its users to find out how they respond to positive and negative messages – without telling participants
Over 600,000 Facebook users have taken part in a psychological experiment organised by the social media company, without their knowledge.
Facebook altered the tone of the users’ news feed to highlight either positive or negative posts from their friends, which were seen on their news feed.
They then monitored the users’ response, to see whether their friends’ attitude had an impact on their own.