text: While it has long been believed in psychology that weather somehow influences human's mood, the debates have been going on for decades about how they are correlated. In this paper, we try to study this long-lasting topic by harnessing a new source of data compared from traditional psychological researches: Twitter. We analyze 2 years' twitter data collected by twitter API which amounts to @math of all postings and try to reveal the correlations between multiple dimensional structure of human mood with meteorological effects. Some of our findings confirm existing hypotheses, while others contradict them. We are hopeful that our approach, along with the new data source, can shed on the long-going debates on weather-mood correlation.
  @cite_35: 
  @cite_8: Abstract We investigated platelet 14 C-serotonin uptake and platelet [ 3 H]LSD and [ 3 H]paroxetine binding in 11 patients with seasonal affective disorder (SAD). Patients were reinvestigated after light therapy, applied at 07.00–09.00 h for 10 consecutive days. The degree of depression was rated before and after light therapy using the Comprehensive Psychopathological Rating Scale (CPRS). Baseline data in patients were compared with data from a control group consisting of 11 age- and sex-matched healthy volunteers. Seven patients responded to light therapy with a>50 reduction in CPRS scores. In non-responders, the reduction in CPRS was 24.7±5.5 . There was a significant inverse correlation ( P =0.014) between K m for platelet 14 C-serotonin uptake and CPRS scores. Patients had significantly higher B max for platelet [ 3 H]LSD binding ( P =0.04) and significantly lower B max for platelet [ 3 H]paroxetine binding ( P =0.016). There was a strong, multiple correlation between B max for [ 3 H]LSD, as the dependent variable, and K m , V max and B max for [ 3 H]paroxetine binding in patients ( P K m ( P =0.023) and significantly lower B max for [ 3 H]paroxetine binding ( P =0.028) than non-responders. B max for [ 3 H]paroxetine binding increased significantly to normal levels after light therapy. The results indicate that SAD is associated with aberrations in the serotonin uptake mechanism. The enhanced 5-HT 2 -receptor density may reflect a consequential up-regulation.
  @cite_10: Summary Alterations in monoaminergic neurotransmission in the brain are thought to underlie seasonal variations in mood, behaviour, and affective disorders. We took blood samples from internal jugular veins in 101 healthy men, to assess the relation between concentration of serotonin metabolite in these samples and weather conditions and season. We showed that turnover of serotonin by the brain was lowest in winter (p=0·013). Moreover, the rate of production of serotonin by the brain was directly related to the prevailing duration of bright sunlight (r=0·294, p=0·010), and rose rapidly with increased luminosity. Our findings are further evidence for the notion that changes in release of serotonin by the brain underlie mood seasonality and seasonal affective disorder.
  @cite_55: Abstract Background: Physical exercise alleviates depressive symptoms, as does exposure to bright light, especially in those with seasonal variation. Our objective was to compare the effect of exercise alone or combined with morning bright light on mood and the health-related quality of life in healthy subjects. Methods: Study subjects were working-age adults, randomized in two groups ( n =80): exercise in bright light (group A), or exercise in normal indoor illumination (group B). Intervention lasted for 8 weeks and questionnaire data on mood and the health-related quality of life were collected at study entry, and at weeks 4 and 8. Results: Physical exercise both in normal indoor illumination and in bright light was effective at alleviating depressive symptoms. The exercise was significantly more effective at alleviating so-called atypical depressive symptoms when combined with bright-light exposure. Limitations: There was no active placebo condition, but a comparative, randomized trial was executed. Conclusions: Physical exercise in bright light had a positive effect on mood and health-related quality of life in a sample of healthy, working-age people. Further research is needed to explore the mechanisms of the apparent additive effect of exercise and light.
  @cite_21: Research has shown that greater degrees of sunshine experienced directly are associated with greater amounts of compliance and tipping. This paper describes two studies that investigated beliefs about sunshine and tipping. The studies were conducted at a casino hotel in Atlantic City; a male server who delivered food and drinks to guests' rooms acted as the confederate. In Study 1, the server reported to guests the actual sky conditions: sunny, partly sunny, cloudy, or rainy. Tip percentages increased linearly from the worst to the best conditions. Study 2 used an experimental design. The server informed guests that the weather was either warm and sunny, cold and sunny, warm and rainy, or cold and rainy. Guests were gullible because their rooms shielded them from the actual conditions. Belief in sunny skies produced greater tip percentages. The temperature belief manipulation had no effect. This research extended previous research by showing that beliefs about weather, in addition to actual weather, can affect behavior.
  @cite_3: The heat hypothesis states that hot temperatures can increase aggressive motives and behaviors. Although alternative explanations occasionally account for some portion of the observed increases in aggression when temperatures are high, none are sufficient to account for most such heat effects. Hot temperatures increase aggression by directly increasing feelings of hostility and indirectly increasing aggressive thoughts. Results show that global warming trends may well increase violent-crime rates. Better climate controls in many institutional settings (e.g., prisons, schools, the workplace) may reduce aggression-related problems in those settings.
  @cite_13: 
  @cite_12: Archival data pertaining to 102 instances of serious collective violence were examined in order to study the relationship between ambient temperature and the occurrence of such events. Results indicated that the frequency of collective violence and ambient temperature were curvilinearly related. Specifically, ambient temperature was directly associated with the frequency of collective violence through the mid-80s (degrees Fahrenheit). Beyond this point, however, further increments in temperature were associated with a decreasing incidence of such events. Additional findings indicated that ambient temperature increased significantly during the 7 days preceding the outbreak of collective violence, remained stable during its occurrence, but then decreased significantly in the 3 days following its termination. Possible implications of these findings, as well as their relationship to the results of previous laboratory studies, are discussed. Language: en
summary: Despite the on-going debates in psychology, most physiologists believe that the weather indeed has significant influence on psychological processes based on strong physiological evidence. For example, @cite_10 spotted rising and dipping production of serotonin, a neurotransmitter in human central nervous system, which is generally thought to be a contributor to feelings of well-being and happiness, as sunlight increased or decreased. Another line of evidence is provided by population-wide behavior studies in social psychology. A good example is seasonal affective disorder (SAD), which refers to the mood disorder in which people who have normal mental health throughout most of the year experience depressive symptoms in the winter http: en.wikipedia.org wiki Seasonal_affective_disorder . Researchers suggest that exposure to sunlight would immediately improve mood and diminishes SAD @cite_35 @cite_10 @cite_55 @cite_8 and that rainy or cloudy days can aggravate the symptoms @cite_55 . Additionally, reliable and significant associations are found between weather and mood-related social behaviors. For example, low barometric pressure @cite_13 and more snow are evidently linked with higher suicide rates @cite_21 and high temperature is associated with violent behavior @cite_3 @cite_12 .