People are happiest at home, and most miserable at work - that's the conclusion of a new study which tracks people’s emotional behaviour through their mobile phones.
The EmotionSense system, developed at the University of Cambridge, uses speech-recognition software and phone sensors in standard smartphones to assess how people's emotions are influenced by their surroundings, the time of day, and their relationships with others.
"Everyone has a mobile phone, so potentially they are a perfect tool if you want to track the behaviour or emotional condition of large numbers of people," said Dr Cecilia Mascolo, who led the research.
EmotionSense uses the recording devices in mobile phones to analyse audio samples of the user speaking. These are compared with an existing, widely-used speech library and grouped into five categories - happiness, sadness, fear, anger and neutral.
The data can then be compared with other information from the phone. GPS software gives the user's location, Bluetooth can be used to identify who they were with, and the phone also records data about who they were talking to and when the conversation took place.
The analysis is carried out on the phone itself to maintain privacy.
Subjects were given a modified Nokia 6210 Navigator phone for a period of 10 days, and asked to keep a diary of their emotional state.
The results showed that in about 70 percent of cases, the emotional analysis offered by the phone system agreed with the results of the survey, suggesting that with a bit more modification the system could be a very accurate means of tracking the factors influencing people's emotions.
The study also threw some light on when and where we're happiest. Happy emotions dominated the data when they were in residential locations, representing 45 percent of all emotions recorded, but in workplaces, sad emotions became the norm, at 54 percent.
The researchers also found that users exhibited more intense emotions in the evening than in the morning, and that people tended to express their emotions far more in smaller groups than in larger crowds.