One giant step in emotion-reading technology: Chinese scientists claim movement-based app can tell anger from happiness in users
Mainland scientists claim to have developed the world's first smartphone app that can detect emotions from body movements.
The research team, led by Professor Zhu Tingshao from the Chinese Academy of Sciences' Institute of Psychology, said the technology had a wide range of applications, such as a "smart bracelet" that could send an alert if a wearer became emotionally unstable.
The Android app could tell if the user was angry, happy or calm with up to 90 per cent accuracy by analysing variations in gait, the researchers said in a paper accepted by Human-Centred Computing, an international conference to be held in Sri Lanka in January.
The app was developed in collaboration with China Electronics Corporation, one of the country's biggest makers of telecom equipment.
Other emotion detection apps on the market identify specific emotions from voice patterns and facial expressions and require active engagement - such as a chat or a selfie - from the user.
But the app built by Zhu's team could "generate daily, weekly or monthly emotion profile reporting how the emotion changes over time" using motion sensors already built into most smartphones to capture body movements.
The app was 90.31 per cent accurate when distinguishing anger from neutral emotions, 89.76 per cent in detecting happiness from neutral emotions, and 87.10 per cent accurate in telling anger from happiness, Zhu reported.
The researchers recruited 59 university students as volunteers to test the technology.
The participants watched a short film designed to make them either happy or angry and then took a two-minute walk with smartphones strapped to their wrists and ankles.
The app compared the results from test subjects with information fed into a database.
The results showed there were limits to the technology, though, and the researchers said in the conference paper that they would continue to refine the algorithm.
They found, for instance, that the results from the wrist phones were unreliable and the devices had to be strapped to the ankle for greatest accuracy. That meant the app could not detect mood when the smartphone was carried in a pocket.
The use of technology also raises serious privacy concerns.
Some companies have sold emotion-detection technology to law enforcers for use in interrogations, while some shopping malls have experimented with it to gauge the mood of customers as they shop.
"I don't mind sharing the number of paces I walk in a day on social media but emotion is another thing. I don't want my boss to be able to know if I am happy or angry after we finish a meeting," a Beijing smartphone user said.
Zhu could not be reached for comment, but in an interview with the South China Morning Post last year he said privacy was the top concern when developing new technology.
"The technology will stay in our lab, and we make sure that it does not fall into the wrong hands," he said.
"But protecting data on emotions is very difficult in China.
"There is no law telling us whether the status of emotion is an area of personal privacy."