Observers Can Learn A Scary Amount About You From How You Move A Mouse


Stephen Luntz

Stephen has a science degree with a major in physics, an arts degree with majors in English Literature and History and Philosophy of Science and a Graduate Diploma in Science Communication.

Freelance Writer

white mouse

Even before you click, your mouse could be revealing your state of mind and therefore how you might respond to future questions. Katerina Fabianova/

We know many companies are learning an inordinate amount about us based on our online clicks. That's unlikely to be the end of it, however, following the discovery that even how you move your mouse may reveal more than you might wish about preferences and future decisions.

In the course of a PhD at Ohio State University, Dr Paul Stillman gave subjects a choice of safe or risky bets. In addition to recording which they chose, he tracked their mouse cursor movements, and found these indicated how certain people were about their choices, and therefore how likely they were to take a different path in future.


“Choice is not a discrete event, but rather the output of a dynamic cognitive process, which is reflected in motor movement,” Stillman and colleagues wrote in their study published in Proceedings of the National Academy of Sciences.

"We could see the conflict people were feeling making the choice through their hand movements with the mouse," Stillman said in a statement. For example, those who were sorely tempted by the high-risk option would often move their cursor towards it, before eventually settling on the safe path. Not surprisingly, these people were far more likely to opt for a risky choice in future than those who went straight to their eventual destination.

"In many cases, we could accurately predict how people would behave in the future after we observed them just once choosing to take a gamble or not," said Stillman's supervisor Dr Ian Krajbich. “It is rare to get predictive accuracy with just a single decision in an experiment like this."

The team had participants place their cursor at the bottom center of the screen. In 215 trials they were then presented with two choices, with the safe option at the top left, and the risky one in the upper right. Some rounds offered a 50/50 chance of gaining or losing money, compared to a neutral outcome. In others, the choice was between a guaranteed small reward and an equal chance of getting more or nothing.


Whether the participants moved the cursor straight to their eventual target or took a roundabout route proved highly predictive of how they would respond in later tests – much more so than traditional measures such as the time required to make a decision.

As the authors note, countless psychological studies have shown most people are both loss-averse (finding the pain of losing greater than the joy of winning) and risk-averse (valuing a $10 win less than twice a $5 one). Yet, perhaps surprisingly, there has been little research into how people make these decisions, including how torn they feel. By tracking their participants' mouse movements, the authors gained insight into the journey, as well as the eventual destination.

The work could open up opportunities to study internal conflict, but it also shows just how careful we need to be about who gets to track our online activity. Those with a vested interest in hooking people on gambling or buying something they can't really afford could find such movements exceptionally useful in identifying the most susceptible targets.