A new twist on an old test.

People are likely to perform better cognitively when under the supervision of a “mean” robot than a “nice” one, according to a study published in Science Robotics on Wednesday.

For their study, the researchers asked 58 young adults to complete the Stroop task, a psychological experiment in which a person sees a word and must state the color of the font. This can be challenging when what the word says and the color it’s written in diverge (for example, when the word “green” appears in a red font). Years of psychology studies have shown that people are better at the test when they’re under stress, either from competitors or simply a human supervisor.

The researchers had the young adults complete the Stroop task twice. The first time, they performed it alone. The second time, they either completed it alone again or with a humanoid robot supervisor in the room.

The participants, it turns out, already had feelings about the robot, because they had hung out with it before the test started. In some cases, this prior interaction was positive — the robot was nice and empathetic, pointing out nice similarities between the participant and the robot (example: three things they have in common? Robot says: “We have arms, two eyes and we are both nice.”). In other instances, the interaction was negative — the robot was contemptuous, lacked empathy, and even made negative comments about the participant’s intelligence.

While the supervised participants completed the task, the robot boss stood off to the side, just within their peripheral vision. Researchers controlled the robot’s motions remotely during the task (for example, instructing it to tilt its head toward the volunteer), and these motions were identical for each participant.

Under pressure.

When volunteers completed the task under the gaze of the pleasant robot supervisor, their performance didn’t improve at all. However, when the “mean” robot was watching, the volunteers’ performance “improved notably,” about the same as in previous Stroop experiments with human supervisors, the study authors note.

According to the study, this could mean that the presence of a less-than-friendly robot can increase a person’s level of alertness as much as a human supervisor can. It’s another datapoint to inform the confusing, sometimes inconsistent ways that humans interact with, and can feel pressured by, our robot brethren.

So, while you might not welcome the idea of your next boss being a bot and not a fellow human, if they’re mean enough, they might help you perform better at work. Then, who knows? Maybe you’ll work you way up to being the robot’s boss.