Watching high-spirited videos on YouTube after a long day at work could pep you up a bit as researchers have found that people mirror the emotions of those they see online. When a YouTuber posts a video with a generally positive tone the audience reacts with heightened positive emotions and the same is true for other emotional states said the study published in the journal Social Psychological and Personality Science. Our research is a reminder that the people we encounter online influence our everyday emotions -- being exposed to happy (or angry) people can make us more happy (or angry)