NYT discusses a paper by Scott Golder and Michael Macy from Cornell University on correlation between the emotional tone of people's messages on Twitter and known biological rhytms (aka cyrcadian rhytms). Using text mining software and impressive sample (several millions of tweets), researchers classified random tweets based on their content (usage of words "awesome", "great' and emoticons) as either "positive" or "negative", and then looked at the patterns throughout the day. They found that for majority of people, positive tweets tend to appear in the morning (between 6 am and 9 am), slowly decline towards afternoon, and then rise again after dinner. In the beginning of the workweek the overall mood tends to be lower, with the curve peaking on weekends. The patterns seem to be the same across different cultures.
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