PT  - JOURNAL ARTICLE
AU  - Golder, Scott A.
AU  - Macy, Michael W.
TI  - Diurnal and Seasonal Mood Vary with Work, Sleep, and Daylength Across Diverse Cultures
AID  - 10.1126/science.1202775
DP  - 2011 Sep 30
TA  - Science
PG  - 1878--1881
VI  - 333
IP  - 6051
4099  - http://science.sciencemag.org/content/333/6051/1878.short
4100  - http://science.sciencemag.org/content/333/6051/1878.full
SO  - Science2011 Sep 30; 333
AB  - We identified individual-level diurnal and seasonal mood rhythms in cultures across the globe, using data from millions of public Twitter messages. We found that individuals awaken in a good mood that deteriorates as the day progresses—which is consistent with the effects of sleep and circadian rhythm—and that seasonal change in baseline positive affect varies with change in daylength. People are happier on weekends, but the morning peak in positive affect is delayed by 2 hours, which suggests that people awaken later on weekends.