A study of nearly 2 million tweets over one year suggests that people in San Francisco feel disgusted when at hardware stores and Londoners are most joyful at hostels or motels
1 February 2023
Your tweets may reveal when and where you are angry, disgusted, sad or joyful.
Believing that tweets hold a “wealth of information” on human behaviour, Panote Siriaraya at the Kyoto Institute of Technology, Japan, and his colleagues analysed the content of tweets posted in San Francisco and London from early September 2016 to late August 2017.
Siriaraya says they used data from this period because Twitter removed precise location tagging from its posts in 2019. The researchers had also already analysed tweets posted between 2016 and 2017 for a previous study, which they reused.
The team drew a boundary around each city, analysing every tweet posted within these geographical areas that wasn’t sent by apps such as Foursquare, which tweets automatically when a user “checks in” using its app.
Overall, the researchers analysed 1.57 million tweets from people in London, posted by 180,000 users, and 390,000 tweets from San Francisco, posted by 65,000 users. According to the researchers, these cities were chosen because they can be accurately traced using OpenStreetMap, a tool that can locate where tweets were sent.
An artificial intelligence known as a neural network classified the content of each tweet according to the emotion it most expressed.
The results suggest that tweets with an angry tone were most commonly posted on Wednesdays among people in San Francisco, compared with Tuesdays for Londoners. This may be explained by people feeling frustrated while getting through a working week, according to the researchers.
Tweets posted on weekends tended to display more positive emotions, such as joy, compared with more commonly expressed negative sentiments, like sadness, on weekdays, which is of little surprise, says Siriaraya.
In San Francisco, people most commonly tweeted posts of disgust when close to real estate agent offices, followed by hardware stores. They also tended to be angrier around the city’s bridges. According to Siriaraya, this anger may be explained by San Francisco’s limited number of bridges causing traffic to build up as people enter and leave the city.
In London, anger was expressed at bus stops, perhaps reflecting frustrations when waiting for public transport, according to the researchers. People in London are most joyful in tourist accommodation venues, such as motels and hostels, the results suggest. Hotels and restaurants were linked to both anger and joy.
The research was carried out at a scale that hasn’t been done before, says David Ellis at the University of Bath, UK. However, Ellis says he would have liked the researchers to approach some of those who tweeted to confirm the neural network correctly classified the emotion behind their post.
Barry Smith at the School of Advanced Study, University of London, also has questions about the classifications of the tweets. “One of the emotions they had is anticipation,” he says. “That’s a funny one, because you can anticipate things with dread or you can anticipate things with pleasure.” The researchers deemed anticipation to be a positive emotion in their study.
Smith also suggests that some of the locations are classified in a way that makes it difficult to discern what is happening around the person posting. For example, tweets containing the word “wine” were associated with sadness in San Francisco and fear in London.
Siriaraya says that the results, and the insights that can be obtained from them, don’t always reflect the complexities of human life and require further research.
Article amended on 2 February 2023
This copy has been updated to more accurately describe the locations in London that bring people on Twitter joy.
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