Early morning tweets are often based on a logical way of thinking, while those in the evenings and nights are high on emotions, finds an analysis of 800-million tweets.
The findings showed that our mode of thinking changes at different times of the day and follows a 24-hour pattern.
At 6am, analytical thinking was shown to peak; the words and language at this time were shown to correlate with a more logical way of thinking.
However, in the evenings and nights this thinking style changed to a more emotional and existential one.
"Circadian rhythms are a major feature of most systems in the human body, and when these are disrupted they can result in psychiatric, cardiovascular and metabolic disease," said Stafford Lightman, Professor at the Britain's University of Bristol.
"The use of media data allows us to analyse neuropsychological parameters in a large unbiased population and gain insights into how mood-related use of language changes as a function of time of day.
"This will help us understand the basis of disorders in which this process is disrupted," Lightman added.
For the study, published in the journal PLOS ONE, the team examined thinking behaviour by analysing seven-billion words used in 800-million tweets.
They found that the tweets starting at around 5am to 6am, depicts expressions with measures of analytical thinking through the high use of nouns, articles and prepositions.
This early-morning period also shows increased concern with achievement and power. On the other hand, the researchers found a more impulsive, social, and emotional mode during evening.
The tweets during evening were correlated with the language of existential concerns but anti-correlated with expression of positive emotions.
Overall, the study found strong evidence that our language changes dramatically between night and day, reflecting changes in our concerns and underlying cognitive and emotional processes, the researchers said.
These shifts also occur at times associated with major changes in neural activity and hormonal levels, suggesting possible relations with our circadian clock.