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Cambridge University Science Magazine
The researchers used language monitoring software to score levels of “positive affect” - which includes feelings such as enthusiasm, alertness and delight - and “negative affect” – such as anger, distress and fear – in tweets written by 2.4 million people in 84 countries, over 2 years. Their results, published in Science, show that people across the world typically wake up happy, with levels of positive affect peaking early in the morning when levels of negative affect are also at their lowest. As soon as the working day begins, however, positive affect decreases, only picking up again in the early evening.

People also seem happiest at the weekend, with most countries’ tweets revealing highest levels of positive affect on Saturday and Sunday. One exception was the United Arab Emirates in which the working week traditionally runs from Sunday to Thursday – tweets there were most positive on Friday and Saturday. It’s not all bad news for the world of work, however: while baseline happiness was higher at the weekend, peoples’ moods still followed much the same daily pattern on weekend days as during the week. This suggests that sleep and circadian rhythms exert considerable influence over our moods.

While there was no relation between the absolute amount of daylight in different countries and peoples’ happiness levels, positive affect did increase within individual countries as the days became longer, and decrease as they became shorter. Negative affect remained relatively stable throughout the year, suggesting that the “winter blues” may reflect a reduction in positive feelings, rather than an increase in negative ones. 

Written by Louisa Lyon

DOI: 10.1126/science.1202775